1 Fig 3 3 fig 0303 cpp 2

1 // Fig. 3. 3: fig 03_03. cpp 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 // Creating and using a programmer-defined function #include <iostream> 1 4 8 using std: : cout; using std: : endl; int square( int ); Notice how parameters and return value are declared. // function prototype int main() { for ( int x = 1; x <= 10; x++ ) cout << square( x ) << " "; cout << endl; return 0; } // Function definition int square( int y ) { return y * y; } Program Output 9 16 25 36 49 64 81 100

1 // Fig. 3. 4: fig 03_04. cpp 2 // Finding the maximum of three integers 3 #include <iostream> 5 1. Function prototype (3 using std: : cout; parameters) 6 using std: : cin; 7 using std: : endl; 4 2. Input values 8 9 int maximum( int, int ); // function prototype 10 11 int main() 2. 1 Call function 12 { 13 int a, b, c; 14 15 cout << "Enter three integers: "; 16 cin >> a >> b >> c; 17 18 // a, b and c below are arguments to 19 // the maximum function call 20 cout << "Maximum is: " << maximum( a, b, c ) << endl; 9

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 return 0; } // Function maximum definition // x, y and z below are parameters to // the maximum function definition int maximum( int x, int y, int z ) { int max = x; if ( y > max ) max = y; if ( z > max ) max = z; return max; } Program Output Enter three integers: 22 85 17 Maximum is: 85 Enter three integers: 92 35 14 Maximum is: 92 Enter three integers: 45 19 98 Maximum is: 98 10

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 // Fig. 3. 7: fig 03_07. cpp // Shifted, scaled integers produced by 1 + rand() % 6 #include <iostream> using std: : cout; using std: : endl; #include <iomanip> using std: : setw; #include <cstdlib> int main() { for ( int i = 1; i <= 20; i++ ) { cout << setw( 10 ) << ( 1 + rand() % 6 ); Program Output. 3 Notice rand() % 6. This returns a number between 0 and 5 (scaling). Add 1 to get a number between 1 and 6. if ( i % 5 == 0 ) cout << endl; } Executing the program again gives the same "random" dice rolls. return 0; } 15 5 2 5 5 5 4 3 1 3 2 2 4 5 5 2 6 5 5 1 4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 2. Input value for seed // Fig. 3. 9: fig 03_09. cpp // Randomizing die-rolling program #include <iostream> using std: : cout; using std: : cin; using std: : endl; 2. 1 Use srand to change random #include <iomanip> sequence using std: : setw; #include <cstdlib> 2. 2 Define Loop int main() { unsigned seed; cout << "Enter seed: "; 3. Generate and output cin >> seed; srand( seed ); random numbers for ( int i = 1; i <= 10; i++ ) { cout << setw( 10 ) << 1 + rand() % 6; if ( i % 5 == 0 ) cout << endl; } 16 } return 0;

Enter seed: 67 1 5 6 6 5 3 1 1 4 2 Enter seed: 432 4 2 2 5 6 1 4 4 3 4 Enter seed: 67 1 5 6 6 5 3 1 1 4 2 Notice how the die rolls change with the seed. Program Output 17

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 // Fig. 3. 10: fig 03_10. cpp // Craps #include <iostream> 1. 1 Initialize variables and enum using std: : cout; using std: : endl; #include <cstdlib> #include <ctime> 1. 2 Seed srand using std: : time; int roll. Dice( void ); // function prototype 2. Define switch statement for win/loss/continue srand( time( 0 ) ); int main() { enum Status { CONTINUE, WON, LOST }; int sum, my. Point; Status game. Status; 20 sum = roll. Dice(); switch ( sum ) { case 7: case 11: game. Status = WON; break; case 2: case 3: case 12: game. Status = LOST; break; Notice how the enum is defined // first roll of the dice // win on first roll // lose on first roll

35 default: // remember point 36 game. Status = CONTINUE; 37 my. Point = sum; 38 cout << "Point is " << my. Point << endl; 39 break; 40 // optional } 41 44 // keep rolling 2. 1 Define loop to sum = roll. Dice(); continue playing 45 if ( sum == my. Point ) 42 while ( game. Status == CONTINUE ) { 43 46 game. Status = WON; 47 2. 2 Print win/loss // lose by rolling 7 else 48 if ( sum == 7 ) 49 50 // win by making point game. Status = LOST; } 51 52 53 54 55 if ( game. Status == WON ) cout << "Player wins" << endl; else cout << "Player loses" << endl; 56 57 21 58 } 59 return 0;

60 int roll. Dice( void ) 61 { 62 int die 1, die 2, work. Sum; 63 64 die 1 = 1 + rand() % 6; 65 die 2 = 1 + rand() % 6; 66 work. Sum = die 1 + die 2; 67 cout << "Player rolled " << die 1 << " + " << die 2 68 << " = " << work. Sum << endl; 69 70 return work. Sum; 71 } Player rolled 6 + 5 = 11 Player wins 3. Define roll. Dice function Player rolled 6 + 5 = 11 Player wins Player rolled Point is 10 Player rolled Player wins 4 + 6 = 10 Player rolled Point is 4 Player rolled Player rolled Player loses 1 + 3 = 4 22 2 6 3 6 1 5 4 6 1 5 + + + + + 4 5 3 4 4 4 6 3 2 2 = = 6 11 6 10 Program Output = = = 5 9 10 9 3 7