KMP模板

#include <stdio.h>void getnext(char *ch, int next[]);int kmp(char *ch1, char *ch2, int next[]);int main(){char ch1[100], ch2[100];int next[100];scanf("%s", ch1);getnext(ch1, next);//获得next数组。scanf("%s", ch2);printf("%d\n", kmp(ch1, ch2, next));return 0;}void getnext(char *ch, int next[])//对匹配串进行kmp匹配获得next数组值{int i, j;i=0;j=-1;next[0] = -1;//初始化，next[0] = -1;while(ch[i]){if(j==-1 || ch[i]==ch[j])//匹配成功时，当前ch[i]对应的next值 变为 匹配成功的ch[j]的下标值。{i++;j++;next[i] = j;}elsej = next[j];//匹配失败则向左移动匹配串，重新寻找，即从next[j]对应的ch[next[j]]开始。}}int kmp(char *ch1, char *ch2, int next[]){int i, j;i=0;j=0;while(ch2[i]){if(j==-1 || ch2[i]==ch1[j])//与上方原理基本相同{i++;j++;if(ch1[j]==0)return (i-j);}elsej = next[j];}return -1;}