kmp算法的bug free版本

#include <cstdio>
#include <cstring>
#include <iostream>
#include<vector>
#include<string>
#include<sstream>
using namespace std;
int n, num, Next[1001001];

int main()
{
    string s, t;
    getline(cin, t);
    cin >> s;
    int m = s.length();
    memset(Next, 0, sizeof(Next));
    int now = Next[0] = -1;
    for (int i = 1; i < m; i++)
    {
        while (now >= 0 && s[now + 1] != s[i]) now = Next[now];
        if (s[now + 1] == s[i]) now++;
        Next[i] = now;
    }
    int n = t.length();
    now = -1;
    int flag = 1;
    for (int i = 0; i < n; i++)
    {
        while (now >= 0 && s[now + 1] != t[i]) now = Next[now];
        if (s[now + 1] == t[i]) now++;
        if (now == m - 1)
        {
            flag = 0;
            cout << i - m + 1 << " ";
            now = Next[now];
        }
    }
    if (flag == 1)
        cout << "false";
}