Submission

Score: 100

User: 666whynot

Problemset: เลขหลักของผลคูณ

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-05 21:01:10

#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);cin.tie(nullptr);
    int a,b;cin>>a>>b;
    long long sum = a*b;
    int x;cin>>x;
    int cnt = 0;
    while(sum > 0){
        sum /= 10;
        cnt++;
    }
    sum = a*b;
    vector<long long> s;
    for(int i=1;i<=cnt;i++){
        int e = sum % 10;
        s.push_back(e);
        sum /= 10;
    }
    int q = 0;
    x--;
    bool qwe;
    reverse(s.begin(),s.end());
    for(auto e:s){
        qwe = false;
        if(q == x){cout << e;break;}
        else q++;qwe = true;
    }
    if(qwe)cout << '_';
}