字符串哈希

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
using namespace std;
typedef unsigned long long ull;
ull base=131;
ull a[10010];
int n,ans=1;
ull hashs(string s) {
    int len=s.length();
    ull ans=0;
    for (int i=0;i<len;i++)
        ans=ans*base+(ull)s[i];
    return ans & 0x7fffffff;
}

int main() {
    string s,t; cin>>s>>t;
    int sum = hashs(t);
    int lens = s.length();
    int lent = t.length();
    for(int i=0;i<=lens-lent;i++) {
        string tmp = s.substr(i,lent);
        int tmpsum = hashs(tmp);
        if(tmpsum == sum) {
            cout<<i+1<<endl;
        }
    }
    return 0;
}