int KMPMatch char T char P T0P0 nT0

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int KMPMatch ( char T[] , char P[] ) { //T[0]和P[0]分别表示长度 n=T[0] ; m=P[0]

int KMPMatch ( char T[] , char P[] ) { //T[0]和P[0]分别表示长度 n=T[0] ; m=P[0] ; //长度 i=j=1; //开始 t 1~p 1 while (i<=n && j<=m) if (T[i]==P[j]) { i++; j++; //继续比较下一位 } else { //ti≠ pj k=next[j]; if (k>0) j=k ; //比较ti和pk: ti~pk else { j=1; i++; } //比较ti+1和p 1: ti+1~p 1 } //endif，endwhile if (j>m) //匹配成功 return i-m; //注意成功时，i和j均多加了1 else return 0; //匹配失败 20 }

§ 4. 3 模式匹配算法 void Get. Next (char p[] , int next[]) { //求模式串P的next数组（递推法）i-主串指针

§ 4. 3 模式匹配算法 void Get. Next (char p[] , int next[]) { //求模式串P的next数组（递推法）i-主串指针 i=1; j=0; next[1]=0; m=P[0]; //模式串长度 while (i<m) //求next[i+1] if (j==0) next[++i]=++j; //next[i+1]=1 else //j>0 if (P[i]==P[j]) next[++i]=++j; //next[i+1]=j+1 else //pi≠pj j=next[j]; } //可改进为书上一样的算法 28

§ 4. 3 模式匹配算法 即可用下述方式节省时间： 当pj=pk时，将next[j]置为next[k] 此过程可重复！ 例： j 1 2 3 4 5

§ 4. 3 模式匹配算法 即可用下述方式节省时间： 当pj=pk时，将next[j]置为next[k] 此过程可重复！ 例： j 1 2 3 4 5 j P next[j] nextval[j] P a a b 1 a next[j] 0 1 2 3 4 2 a 0 1 0 0 ti≠p 2, 比较ti~pnext[2] ∵p 2=p 1, next[2] ←next[1] ti ≠p 3, ti~pnext[3], ∵p 3=p 2∴next[3]←next[2] 改进 nextval[j] 0 0 4 3 a 2 0 pj p 2 p 3 p 4 p 5 4 a 3 0 pk p 1 p 2 p 3 p 4 5 b 4 4 30

§ 4. 3 模式匹配算法 n 求nextval算法 与书上不一样的算法，请比较 void Get. Next. Val (char P[], int

§ 4. 3 模式匹配算法 n 求nextval算法 与书上不一样的算法，请比较 void Get. Next. Val (char P[], int nextval[]) { //求nextval i=1; j=0; nextval[1]=0; m=P[0]; while (i<m) { //已知nextval[i]，求nextval[i+1] while (j>0 && P[i] != P[j]) j=nextval[j]; // 出循环时j=0或P[i]=P[j] i++; j++; if (P[i] ==P[j]) nextval[i] = nextval[j]; // 性质 5 else nextval[i] = j; // nextval[i+1] = j+1 } } 31 时间仍为O(m)

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char c char a5 int i int b5char c char a5 int i int b5
char c char a5 int i int b5char c char a5 int i int b5
CLASS 5 int myabsint int rectint int intCLASS 5 int myabsint int rectint int int
typedef int Int A10 Int A a Inttypedef int Int A10 Int A a Int
int mainvoid int x2 xinitial2 int p5 intint mainvoid int x2 xinitial2 int p5 int
IO int a7 int b6 int c5 intIO int a7 int b6 int c5 int
CLASS 5 int myabsint int rectint int intCLASS 5 int myabsint int rectint int int
int add 3 int a int b intint add 3 int a int b int
char a char p new char p achar a char p new char p a
char a char b3 char c a b0char a char b3 char c a b0
char Name30 char MPhone Num20 struct friend charchar Name30 char MPhone Num20 struct friend char
struct STUDENTINFO char id16 char name16 int scorestruct STUDENTINFO char id16 char name16 int score
P 51 char unsigned char short int unsignedP 51 char unsigned char short int unsigned
HCComputeSelection n int HCComputeSelectionconst char display const charHCComputeSelection n int HCComputeSelectionconst char display const char
o o o char c char ansy into o o char c char ansy int
Typedef unsigned char BOOLEAN Typedef unsigned char INTTypedef unsigned char BOOLEAN Typedef unsigned char INT
P 51 char unsigned char short int unsignedP 51 char unsigned char short int unsigned
int main char s 1 Hello char sint main char s 1 Hello char s
struct Student int num char name20 char sexstruct Student int num char name20 char sex
struct student char name30 int height int weightstruct student char name30 int height int weight
int doubletype expression struct char name20 int heightint doubletype expression struct char name20 int height
int transform char key int number 0 whileint transform char key int number 0 while