#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxsize 100

typedef struct {
    char chr[maxsize];
    int  len;
}sqstring;

void get_next(sqstring patternT, int next[]);
int kmfindex(sqstring patternS, sqstring patternT);

void get_next(sqstring patternT, int next[]){
    int j = 0;
    int k = -1;
    next[0] = -1;

    while(j < patternT.len){
        if (k == -1 || patternT.chr[j] == patternT.chr[k]) {
            j++;
            k++;
            next[j] = k;
        }
        else {
            k = next[k];
        }

    }


}
int kmfindex(sqstring patternS,sqstring patternT){
    int next[maxsize];
    int j = 0;
    int i = 0;
    int v;

    get_next(patternT,next);
    while(j < patternT.len && i < patternS.len){
       if( j == -1 || patternS.chr[i] == patternT.chr[j]){
           i++;
           j++;
       }
       else j = next[j];
    }
    if(j >= patternT.len) v = i - patternT.len;
    else v = -1;
    return  v;
}

int main(){
    int k;
    sqstring patternS = {"hello this is kmf,do want to know about it, please try to look carefullycareful"};
    sqstring patternT ={"carefullycareful"};
    patternS.len = strlen(patternS.chr);
    patternT.len = strlen(patternT.chr);

    freopen("C:\\Users\\fangfanglou\\Desktop\\kmf.txt", "r", stdin);
    freopen("C:\\Users\\fangfanglou\\Desktop\\kmf.txt", "w", stdout);
    k = kmfindex(patternS, patternT);
    printf("\n 找到对应字符串的位置了： %d\n", k);
    printf("very 棒球");
    fclose(stdin);
    fclose(stdout);
    return 0;
}