kmp算法

#include <iostream>#include <string.h>using namespace std;void CalNext(const char *pattern, int next[]){    int j=0;    int len = strlen(pattern);    next[0]=-1;    int k=-1;    while(j < len-1){        if((k==-1) || pattern[k] == pattern[j]){            //对啊。一直遍历嘛。所以要一直++            ++k;            ++j;            next[j] = k;        }else{            k = next[k];//递归        }    }}int KMP(int next[], const char *text, const char *pattern){    int i=0,j=0,ans=0;    int n = strlen(text);    int len = strlen(pattern);    while(i<n){        //if(j==-1 || text[i]==pattern[i]){        if(j==-1 || text[i]==pattern[j]){            ++i;            ++j;        }else{            j = next[j];        }        if(j==len){            ans = i-len;            break;        }    }    return ans;}int main(){    int next[5];    char str[]="abcdabaabef";    char *text = "abcdabaabef";    char *pattern = "abaab";    CalNext(pattern,next);    cout<<"位置"<<KMP(next, str, pattern)<<endl;    cout<<"位置"<<KMP(next, text, pattern)<<endl;    return 0;}