1 Arrays Outline Examples Using Arrays Passing arrays

1 Arrays Outline Examples Using Arrays Passing arrays to functions Class Grade. Book: store student grades Searching Arrays—Linear search Sorting Arrays Midterm Solution 2003 Prentice Hall, Inc. All rights reserved.

Using character arrays to store and manipulate strings • string has been used to store character strings – A string such as “Hello” is an array of characters • A character array can be declared and initialized as: – char string 1[] = “first”; – The size of array string 1 is not explicitly defined, but it is determined by the compiler based on the length of the string. – NOTE: • all strings represented by a character array ends with a special character (the null character ‘’) • A character array representing a string should be defined large enough to hold the number of characters in the string + the termination character 2003 Prentice Hall, Inc. All rights reserved. 2

Using character arrays to store and manipulate strings • One could also use this method to declare strings: char string 1[] = {‘f’, ‘i’, ‘r’, ‘s’, ‘t’, ‘’}; If you don’t use ‘’, the array would simply represent an array of characters, not a string! if you specify the size of string 1 and the size of “list of initializers” is larger syntax error • char arrays can be manipulated as other arrays, example: – string[0] = ‘f’; 2003 Prentice Hall, Inc. All rights reserved. 3

Using character arrays to store and manipulate strings • Input from keyboard char string 2[ 20 ]; cin >> string 2; – Puts user input in string • Stops at first whitespace character • Adds null character – If too much text entered, data written beyond array • We want to avoid this • Printing strings – cout << string 2 << endl; • Does not work for other array types – Characters printed until null found 2003 Prentice Hall, Inc. All rights reserved. 4

1 2 3 4 5 6 // Fig. 7. 12: fig 07_12. cpp // treating character arrays as strings. #include <iostream> using std: : cout; using std: : cin; using std: : endl; Outline 7 8 int main() 9 { 10 char string 1 [20]; // reserve 20 characters 11 char string 2 [] = “string literal”; // reserve 15 characters 12 13 14 15 // read string from user into array string 1 cout << “Enter the string “hello there”: ” ; cin >> string 1; // read “hello” [space terminates input] 16 17 18 19 // output strings cout << “string 1 is: ” << string 1 << “nstring 2 is: ” << string 2; cout << “nstring 1 with spaces between characters is: n” ; 20 21 22 23 // output characters until null character is reached for ( int i = 0; string 1[ i ]!= ‘’; i++ ) cout << string 1[ i ] << ‘ ’; 24 25 26 cin >> string 1; // reads “there” cout << “nstring 1 is: ” << string 1 <<endl; 27 28 29 return 0; // indicates successful termination } // end main 2003 Prentice Hall, Inc. All rights reserved. 5

Enter the string “hello there”: hello there string 1 is: hello string 2 is: string literal string 1 with spaces between characters is: h e l l o string 1 is: there Outline 2003 Prentice Hall, Inc. All rights reserved. 6

7 Static and automatic local variables • Recall static storage – If static, local variables save values between function calls – Visible only in function body – Can declare local arrays to be static • Initialized to zero static int array[3]; • If not static – Created (and destroyed) in every function call 2003 Prentice Hall, Inc. All rights reserved.

1 2 3 // Fig. 7. 13: fig 07_13. cpp // Static arrays are initialized to zero. #include <iostream> 4 5 6 using std: : cout; using std: : endl; 7 8 9 void static. Array. Init( void ); void automatic. Array. Init( void ); 10 11 12 13 14 15 int main() { cout << "First call to each function: n" ; static. Array. Init(); automatic. Array. Init(); // function prototype 16 17 18 19 20 cout << "nn. Second call to each function: n" ; static. Array. Init(); automatic. Array. Init(); cout << endl; 21 22 return 0; 23 24 Outline // indicates successful termination } // end main 25 2003 Prentice Hall, Inc. All rights reserved. 8

26 27 28 29 30 // function to demonstrate a static local array Static array, initialized to zero void static. Array. Init( void ) on first function call. { // initializes elements to 0 first time function is called static int array 1[ 3 ]; 31 32 cout << "n. Values on entering static. Array. Init: n"; 33 34 35 36 // output contents of array 1 for ( int i = 0; i < 3; i++ ) cout << "array 1[" << i << "] = " << array 1[ i ] << " 37 38 cout << "n. Values on exiting static. Array. Init: n"; 39 40 41 42 43 // modify and output for ( int j = 0; j < cout << "array 1[" << ( array 1[ 44 45 Outline "; Array data is changed; the modified values stay. contents of array 1 3; j++ ) << j << "] = " j ] += 5 ) << " "; } // end function static. Array. Init 46 2003 Prentice Hall, Inc. All rights reserved. 9

47 48 49 50 51 // function to demonstrate an automatic local array void automatic. Array. Init( void ) Automatic array, recreated { with every function call. // initializes elements each time function is called int array 2[ 3 ] = { 1, 2, 3 }; 52 53 cout << "nn. Values on entering automatic. Array. Init: n"; 54 55 56 57 // output contents of array 2 for ( int i = 0; i < 3; i++ ) cout << "array 2[" << i << "] = " << array 2[ i ] << " 58 59 cout << "n. Values on exiting automatic. Array. Init: n"; 60 61 62 63 64 // modify and output for ( int j = 0; j < cout << "array 2[" << ( array 2[ 65 66 contents of array 2 3; j++ ) << j << "] = " j ] += 5 ) << " "; Outline "; Although the array is changed, it will be destroyed when the function exits and the changes will be lost. } // end function automatic. Array. Init 2003 Prentice Hall, Inc. All rights reserved. 10

First call to each function: Values on array 1[0] entering static. Array. Init: = 0 array 1[1] = 0 array 1[2] = 0 exiting static. Array. Init: = 5 array 1[1] = 5 array 1[2] = 5 Values on array 2[0] entering automatic. Array. Init: = 1 array 2[1] = 2 array 2[2] = 3 exiting automatic. Array. Init: = 6 array 2[1] = 7 array 2[2] = 8 Outline Second call to each function: Values on array 1[0] entering static. Array. Init: = 5 array 1[1] = 5 array 1[2] = 5 exiting static. Array. Init: = 10 array 1[1] = 10 array 1[2] = 10 Values on array 2[0] entering automatic. Array. Init: = 1 array 2[1] = 2 array 2[2] = 3 exiting automatic. Array. Init: = 6 array 2[1] = 7 array 2[2] = 8 2003 Prentice Hall, Inc. All rights reserved. 11

12 Passing Arrays to Functions • Specify name without brackets – To pass array my. Array to my. Function int my. Array[ 24 ]; my. Function( my. Array, 24 ); – Array size usually passed, but not required • Useful to iterate over all elements 2003 Prentice Hall, Inc. All rights reserved.

13 Passing Arrays to Functions • Arrays passed-by-reference – Functions can modify original array data – Value of name of array is address of first element • Function knows where the array is stored • Can change original memory locations • Individual array elements passed-by-value – Like regular variables – square( my. Array[3] ); 2003 Prentice Hall, Inc. All rights reserved.

14 Passing Arrays to Functions • Functions taking arrays – Function prototype • void modify. Array( int b[], int array. Size ); • void modify. Array( int [], int ); – Names optional in prototype • Both take an integer array and a single integer – No need for array size between brackets • Ignored by compiler – If declare array parameter as const • Cannot be modified (compiler error) • void do. Not. Modify( const int [] ); 2003 Prentice Hall, Inc. All rights reserved.

1 2 3 // Fig. 7. 14: fig 07_14. cpp // Passing arrays and individual array elements to functions. #include <iostream> 4 5 6 using std: : cout; using std: : endl; 7 8 #include <iomanip> 9 10 using std: : setw; 11 12 13 void modify. Array( int [], int ); void modify. Element( int ); 14 15 16 17 18 int main() { const int array. Size = 5; int a[ array. Size ] = { 0, 1, 2, 3, 4 }; Outline Syntax for accepting an array in parameter list. // appears strange // size of array a // initialize a 19 20 21 cout << "Effects of passing entire array by reference: " << "nn. The values of the original array are: n" ; 22 23 24 25 // output original array for ( int i = 0; i < array. Size; i++ ) cout << setw( 3 ) << a[ i ]; 2003 Prentice Hall, Inc. All rights reserved. 15

26 27 28 29 30 31 32 cout << endl; // pass array a to modify. Array( a, array. Size ); Pass array name (a) and size to function. Arrays are passed by-by-reference cout << "The values of the modified array are: n" ; 33 34 35 36 // output modified array for ( int j = 0; j < array. Size; j++ ) cout << setw( 3 ) << a[ j ]; 37 38 39 40 41 // output value of a[ 3 ] cout << "nnn" << "Effects of passing array element by value: " Pass a single array element << "nn. The value of a[3] is " << a[ 3 ] << 'n'; 42 43 44 // pass array element a[ 3 ] by modify. Element( a[ 3 ] ); 45 46 47 // output value of a[ 3 ] cout << "The value of a[3] is " << a[ 3 ] << endl; 48 49 return 0; 50 51 Outline by value; the original cannot be modified. value // indicates successful termination } // end main 2003 Prentice Hall, Inc. All rights reserved. 16

52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 // in function modify. Array, "b" points to // the original array "a" in memory void modify. Array( int b[], int size. Of. Array ) { // multiply each array element by 2 for ( int k = 0; k < size. Of. Array; k++ ) b[ k ] *= 2; Although named b, the array points to the original array a. It can modify a’s data. Outline } // end function modify. Array Individual array elements are passed in function modify. Element, "e" is a local copybyofvalue, and the array element a[ 3 ] passed from main originals cannot be changed. // // void modify. Element( int e ) { // multiply parameter by 2 cout << "Value in modify. Element is " << ( e *= 2 ) << endl; } // end function modify. Element 2003 Prentice Hall, Inc. All rights reserved. 17

Effects of passing entire array by reference: The values of 0 1 2 3 The values of 0 2 4 6 Outline the original array are: 4 the modified array are: 8 Effects of passing array element by value: The value of a[3] is 6 Value in modify. Element is 12 The value of a[3] is 6 2003 Prentice Hall, Inc. All rights reserved. 18

1 2 3 // Fig. 7. 15: fig 07_15. cpp // Demonstrating the const type qualifier. #include <iostream> 4 5 6 using std: : cout; using std: : endl; 7 8 void try. To. Modify. Array( const int [] ); 9 10 11 12 int main() { int a[] = { 10, 20, 30 }; 13 14 try. To. Modify. Array( a ); 15 16 cout << a[ 0 ] << ' ' << a[ 1 ] << ' ' << a[ 2 ] << 'n'; 17 18 return 0; 19 20 // Outline Array parameter declared as const. Array cannot be modified, even though it is passed byprototype reference. function // indicates successful termination } // end main 21 2003 Prentice Hall, Inc. All rights reserved. 19

22 23 24 25 26 27 28 29 30 // In function try. To. Modify. Array, "b" cannot be used // to modify the original array "a" in main. void try. To. Modify. Array( const int b[] ) { b[ 0 ] /= 2; // error b[ 1 ] /= 2; // error b[ 2 ] /= 2; // error Outline } // end function try. To. Modify. Array d: cpphtp 7_examplesch 07Fig 07_15. cpp(26) : error C 2166: l-value specifies const object d: cpphtp 7_examplesch 07Fig 07_15. cpp(27) : error C 2166: l-value specifies const object d: cpphtp 7_examplesch 07Fig 07_15. cpp(28) : error C 2166: l-value specifies const object 2003 Prentice Hall, Inc. All rights reserved. 20

Class Grade. Book: store student grades Outline 1 // Grade. Book. h 2 // Definition of class Grade. Book that uses an array to store test grades 3 // Member functions are defined in Grade. Book. cpp 4 5 #include <string> 6 using std: : string; 7 // Grade. Book Class definition 8 Class Grade. Book Defined as public: it is 9 { accessible to the user of the 10 public: 11 // const. Number of students who took class the test 12 const static int students = 10; 13 // constructor initializes course. Name 14 Grade. Book( string, const int [] ); 15 void set. Course. Name(string); // Function that sets the course name 16 string get. Course. Name(); // Function that gets the course name 17 void display. Message(); // Function that displays a welcome message 18 void process. Grades(); // perform various operations on the grades 19 int get. Minimum(); // find the minimum grade of the test 20 int get. Maximum(); // find the maximum grade of the test 21 double get. Average(); // determine the average grade of the test 22 void output. Bar. Chart(); // output bar char for grade distribution 23 void output. Grades(); // output the content of the grades array 24 private: 25 string course. Name; // course name of this Grade. Book 26 int grades [students]; // array of student grades 27 }; // end class Grade. Book 2003 Prentice Hall, Inc. All rights reserved. 21

1 2 3 4 5 6 7 8 // Grade. Book. cpp // Member function definitions for class Grade. Book that // uses array to store test grades #include <iostream> using std: : cout; using std: : cin; using std: : endl; using std: : fixed; 9 10 11 12 #include <iomanip> using std: : setprecision; using std: : setw; 13 14 #include “Grade. Book. h” 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 // Constructor initializes course. Name with string supplied as argument; // initializes counter data members to 0; Grade. Book: : Grade. Book(string name, cont int grades. Array[] ) { set. Course. Name(name); //initialize course. Name //copy grades from grade. Array to grades data member for ( int grade = 0; grade < students; grade ++ ) grades[ grade ] = grades. Array [ grade ]; } // End constructor // function to set the course name void Grade. Book: : set. Course. Name(string name) { course. Name = name; //store name in the course. Name } 2003 Prentice Hall, Inc. All rights reserved. 22

23 30 31 32 33 34 35 // Function that gets the course name String Grade. Book: : get. Course. Name () { return course. Name; // store the object’s course name } // end function get. Course. Name 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 // Function that displays a welcome message void Grade. Book: : display. Message () { // call get. Course. Name to get the course. Name cout << “Welcome to the grade book forn" << get. Course. Name()<<"!“ <<endl; } // end function display. Message Print contents of grades // perform various operation on thethe data void Grade. Book: : process. Gradesarray () { output. Grades(); // output grades array cout << “n. Class Average is "<< setprecision (2) << fixed << get. Average. Grade()<< endl; cout << “Lowest Grade is "<< get. Minimum() << “n. Highest Grade is "<< get. Maximum()<< endl; output. Bar. Chart(); // call function to print grade distribution } // end function process. Grades 2003 Prentice Hall, Inc. All rights reserved.

54 // find minimum grade 55 int Grade. Book: : get. Minimum() 56 { 57 int low. Grade = 100 ; //assume lowest grade is 100 58 //loop through grades array 59 for ( int grade = 0; grade < students; grade ++ ) 60 { 61 //if current grade lower than low. Grade, assign it to low. Grade 62 if ( grades[ grade ] < low. Grade ) 63 low. Grade = grades[ grade ] ; 64 } 65 return low. Grade; 66 } 67 // find maximum grade 68 int Grade. Book: : get. Maximum() 69 { 70 int high. Grade = 0; //assume highest grade is 100 71 //loop through grades array 72 for ( int grade = 0; grade < students; grade ++ ) 73 { 74 //if current grade higher than high. Grade, assign it to high. Grade 75 if ( grades[ grade ] > high. Grade ) 76 high. Grade = grades[ grade ] ; 77 } 78 return high. Grade; 79 } 2003 Prentice Hall, Inc. All rights reserved. 24

80 81 82 83 84 85 86 87 88 89 90 // find average grade double Grade. Book: : get. Average() { int total = 0 ; //initialize total //sum grades in array for ( int grade = 0; grade < students; grade ++ ) { total += grades[ grade ] ; } return static_cast<double> (total)/student; } 2003 Prentice Hall, Inc. All rights reserved. 25

91 void Grade. Book: : output. Bar. Chart () 92 { 93 cout << “Grade Distribution: " << endl; 94 const int frequency. Size = 11; 95 int frequency[frequency. Size] = { 0 }; 96 97 cout << “Grade Distribution: " << endl; 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 // for each grade frequency, print bar in chart for ( int count = 0; count < frequency. Size; count++ ) { if (count == 0) cout << “ 0 -9: ”; else if (count == 10) cout << “ 100: ”; else cout << count * 10 << “-” << (count * 10) + 9<< “: ”; // print bar of asterisks for ( int stars = 0; stars < frequency[ count ]; stars++ ) cout << '*'; Loop over the grades array, increment the counter for // for each grade increment the appropriate frequency that fall in the for ( int grade = 0; grade < students ; grade++grades ) appropriate range frequency [ grades [ grade ] / 10 ]++; 113 114 115 116 117 cout << endl; // start next line of output } } 2003 Prentice Hall, Inc. All rights reserved. 26

118 119 120 121 122 123 124 125 126 127 // output the contents of the grades array void Grade. Book: : output. Grades() { cout << “n. The Grades are: nn"; //output each student’s grade for ( int student = 0; student < students; student ++ ) cout << “Student "<< setw(2)<< student + 1 << “: " << setw(3) << grades[student]<<endl; } 2003 Prentice Hall, Inc. All rights reserved. 27

1 2 3 // figure 07_18. cpp // Create GRade. Book object using an array of grades #include “Grade. Book. h” // include definition of class Analysis 4 Size of array “students” is a 5 int main() public variable and it is 6 { accessed in the main function 7 // array of student grades 8 int grades. Array[ Grade. Book: : students ] = 9 {87, 68, 94, 100, 83, 78, 85, 91, 76, 87}; 10 Grade. Book my. Grade. Book(“MECH 215 Introduction to C++ Programming“ , grades. Array); 11 my. Grade. Book. display. Message (); 12 my. Grade. Book. process. Grades (); 13 return 0; 14 } // end main 2003 Prentice Hall, Inc. All rights reserved. 28

Welcome to the grade book for MECH 215 Introduction to C++ Programming! The grades are: Student 1: 87 Student 2: 68 Student 3: 94 Student 4: 100 Student 5: 83 Student 6: 78 Student 7: 85 Student 8: 91 Student 9: 76 Student 10: 87 Class average is 84. 90 Lowest grade is 68 Highest grade is 100 Grade 0 -9: 10 -19: 20 -29: 30 -39: 40 -49: 50 -59: 60 -69: 70 -79: 80 -89: 90 -99: 100: distribution * * * * * 2003 Prentice Hall, Inc. All rights reserved. 29

30 Searching Arrays—Linear search • Search array for a “key value” • Linear search – Compare each element of array with key value (search key) • The element we are searching for is likely to be at any position in the array • Start at one end, go to other – Useful for small and unsorted arrays • Inefficient • If search key not present, examines every element – Binary search improves efficiency • It works on sorted arrays 2003 Prentice Hall, Inc. All rights reserved.

31 Searching Arrays—Binary search • Binary search – Only used with sorted arrays – Compare middle element with key • If equal, match found • If key < middle – Repeat search on first half of array • If key > middle – Repeat search on last half – Very fast • At most N steps, where 2 N > # of elements • 30 element array takes at most 5 steps 25 > 30 2003 Prentice Hall, Inc. All rights reserved.

1 2 3 // Fig. 7. 19: fig 07_19. cpp // Linear search of an array. #include <iostream> 4 5 6 7 using std: : cout; using std: : cin; using std: : endl; 8 9 int linear. Search( const int [], int ); 10 11 12 13 14 15 int main() { const int array. Size = 100; int a[ array. Size ]; int search. Key; Outline Takes array, search key, and array size. // prototype // size of array a // create array a // value to locate in a 16 17 18 for ( int i = 0; i < array. Size; i++ ) a[ i ] = 2 * i; 19 20 21 cout << "Enter integer search key: " ; cin >> search. Key; 22 23 24 // attempt to locate search. Key in array a int element = linear. Search( a, search. Key, array. Size ); // create some data 25 2003 Prentice Hall, Inc. All rights reserved. 32

26 27 28 29 30 // display results if ( element != -1 ) cout << "Found value in element " << element << endl; else cout << "Value not found" << endl; 31 32 return 0; 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Outline // indicates successful termination } // end main // compare key to every element of array until location is // found or until end of array is reached; return subscript of // element if key or -1 if key not found int linear. Search( const int array[], int key, int size. Of. Array ) { for ( int j = 0; j < size. Of. Array; j++ ) if ( array[ j ] == key ) return j; return -1; // if found, // return location of key // key not found } // end function linear. Search 2003 Prentice Hall, Inc. All rights reserved. 33

Enter integer search key: 36 Found value in element 18 Outline Enter integer search key: 37 Value not found 2003 Prentice Hall, Inc. All rights reserved. 34

35 Sorting Arrays • Sorting data – Important computing application – Virtually every organization must sort some data • Massive amounts must be sorted • Insertion sort (sinking sort) – Several passes through the array – Successive pairs of elements are compared • If increasing order (or identical), no change • If decreasing order, elements exchanged – Repeat these steps for every element 2003 Prentice Hall, Inc. All rights reserved.

36 Sorting Arrays • Example: – Go left to right, and exchange elements as necessary • One pass for each element – – – Original: 3 4 2 7 6 Pass 1: 3 2 4 6 7 (elements exchanged) Pass 2: 2 3 4 6 7 Pass 3: 2 3 4 6 7 (no changes needed) Pass 4: 2 3 4 6 7 Pass 5: 2 3 4 6 7 2003 Prentice Hall, Inc. All rights reserved.

37 Sorting Arrays • Swapping variables int x = 3, y = 4; y = x; x = y; • What happened? – Both x and y are 3 – Need a temporary variable • Solution int x = 3, temp = x; x = y; y = temp; y = 4, temp; // temp gets 3 // x gets 4 // y gets 3 2003 Prentice Hall, Inc. All rights reserved.

1 2 3 // Fig. 7. 20: fig 07_20. cpp // This program sorts an array's values into ascending order. #include <iostream> 4 5 6 using std: : cout; using std: : endl; 7 8 #include <iomanip> 9 10 using std: : setw; 11 12 13 14 15 16 int main() { const int array. Size = 10; // size of array a int a[ array. Size ] = { 2, 6, 4, 8, 10, 12, 89, 68, 45, 37 }; int hold; // temporary location used to swap array elements 17 18 cout << "Data items in original ordern" ; 19 20 21 22 // output original array for ( int i = 0; i < array. Size; i++ ) cout << setw( 4 ) << a[ i ]; Outline 23 2003 Prentice Hall, Inc. All rights reserved. 38

24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Outline // loop to control number of passes for ( i = 0; i < array. Size; i++ ) // loop to control number of comparisons per pass for ( int j = i+1; j < array. Size; j++ ) // compare side-by-side elements and swap them if element on the left If the // first element is greater than second element (index j) is smaller than the if ( a[ j ] < a[ i ] ) { element on the right (index i), hold = a[ j ]; then we swap them. a[ j ] = a[ i ]; Remember the need of a temp a[ i ] = hold; variable. } // end if 39 2003 Prentice Hall, Inc. All rights reserved. 39

40 cout << "n. Data items in ascending ordern" ; 41 42 43 44 // output sorted array for ( int k = 0; k < array. Size; k++ ) cout << setw( 4 ) << a[ k ]; 45 46 cout << endl; 47 48 return 0; 49 50 Outline // indicates successful termination } // end main Data items in original order 2 6 4 8 10 12 89 68 45 37 Data items in ascending order 2 4 6 8 10 12 37 45 68 89 2003 Prentice Hall, Inc. All rights reserved. 40

1 2 3 // Fig. 7. 20: fig 07_20. cpp (ANOTHER METHOD) // This program sorts an array's values into ascending order. #include <iostream> 4 5 6 using std: : cout; using std: : endl; 7 8 #include <iomanip> 9 10 using std: : setw; 11 12 13 14 15 16 int main() { const int array. Size = 10; // size of array a int data[ array. Size ] = { 2, 6, 4, 8, 10, 12, 89, 68, 45, 37 }; int insert; // temporary location used to swap array elements 17 18 cout << "Data items in original ordern" ; 19 20 21 22 // output original array for ( int i = 0; i < array. Size; i++ ) cout << setw( 4 ) << data[ i ]; Outline 23 2003 Prentice Hall, Inc. All rights reserved. 41

24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 // loop over the element of the array for ( int next = 1; next < array. Size; next++ ) { insert = data[ next ]; // store the value in the current element int move. Item = next; // initialize location to place element Outline // search for the location in which to put the current element while (( move. Item > 0 ) && (data[move. Item - 1 ] > insert ) { // shift element one slot to the right data [move. Item] = data[move. Item - 1]; move. Item-} data [move. Item] = insert; } // end for 2003 Prentice Hall, Inc. All rights reserved. 42

40 cout << "n. Data items in ascending ordern" ; 41 42 43 44 // output sorted array for ( int i = 0; i < array. Size; i++ ) cout << setw( 4 ) << data[ i ]; 45 46 cout << endl; 47 48 return 0; 49 50 Outline // indicates successful termination } // end main Data items in original order 2 6 4 8 10 12 89 68 45 37 Data items in ascending order 2 4 6 8 10 12 37 45 68 89 2003 Prentice Hall, Inc. All rights reserved. 43

// Recursive solution for linear int linear. Search. Recursive( const int main() { const int array. Size = 100; int a[ array. Size ]; int search. Key; search int [], int ); // size of array a // create array a // value to locate in a for ( int i = 0; i < array. Size; i++ ) // create some data a[ i ] = 2 * i; cout << "Enter integer search key: "; cin >> search. Key; int element = linear. Search. Recursive( a, search. Key, 0, array. Size - 1); // display results if ( element != -1 ) cout << "Found value in element " << element << endl; else cout << "Value not found" << endl; return 0; // indicates successful termination } // Recursive function for array search int linear. Search. Recursive( const int array[], int key, int low, int high ) { if (array[low] == key) return low; else if (low == high) return -1; else return linear. Search. Recursive(array , key, low + 1, high); } 2003 Prentice Hall, Inc. All rights reserved. 44