【KMP】

char S[100] = "oooSusakeooo", P[100] = "Susake";
int s_next[100];

int KMP(int pos, int len1, int len2){
    int i = pos, j = 1, k = 0;
    s_next[1] = 0;
    while (j < len1)
    if (k == 0 || P[k - 1] == P[j - 1]) j++, k++, s_next[j] = k;
    else k = s_next[k];

    j = 1;
    while (i <= len2 && j <= len1){
        if (j == 0 || S[i - 1] == P[j - 1]) i++, j++;
        else j = s_next[j];
    }
    return j > len1 ? i - len1 : 0;
}
//KMP(0, strlen(P), strlen(S));