接上一篇hihocoder上KMP算法题，这段代码本地测试通过，提交超时，难道仅仅是因为用了string而不是数组？如果时间限制这么严格倒是说一下啊，还以为算法有问题！

#include<iostream>

#include<string>
using namespace std;
void kmpNext(string pattern, int* p){
    p[0] = 0;
    int k = 0, m = pattern.size();
    for(int i = 1; i < m; i++){
        while(k > 0 && pattern[k] != pattern[i]){
            k = p[k-1];
        }
        if(pattern[k] == pattern[i]){
            p[i] = ++k;
        }else{
            p[i] = 0;//k == 0
        }
    }
}
int kmp(string str, int start, string pattern, int k, int *p){
int i = start, n = str.size(), m = pattern.size();
while(i < n){
while(k > 0 && str[i] != pattern[k]) k = p[k-1];
if(str[i] == pattern[k]){
k++;
if(k == m) return i - m + 1;
}
i++;
}
return -1;
}
int match(string str, string pattern, int *p){
    int ret = 0;
int i = 0;
int k = 0;
int n = str.size(), m = pattern.size();
    while(i < n){
int idx = kmp(str, i, pattern, k, p);
if(idx == -1) break;
ret++;
k = p[m-1];
i = idx + m;
}
    return ret;
}
int main(){
    int N;
    cin >> N;
    int p[10001];
    string pattern;
    string str;
    
    for(int i = 0; i < N; i++){
        cin >> pattern;
        cin >> str;
        // int m = strlen(pattern);
        kmpNext(pattern, p);
        int num = match(str, pattern, p);
        cout<<num<<endl;
    }

}