Submission

Score: 100

User: FIrmTInn

Problemset: เลขหลักของผลคูณ

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-13 22:47:00

#include<iostream>
#include<vector>
using namespace std;
int main(){
    long long n1,n2,prod,count = 0;
    int a;
    cin >> n1 >> n2;
    cin >> a;
    prod = n1*n2;
    int idx = 0;
    vector<int> arr;
    for(int i=prod;i>0;i/=10){
        arr.push_back(i % 10);
        count++;
    }
    int n = arr.size();
    vector<int> arr2(n);
    for(int i=arr.size()-1;i>=0;i--){
        arr2[idx] = arr[i];
        idx++;
    }
    if(a > n){
        cout << '_';
        return 0;
    }
    cout << arr2[a-1];

    return 0;
}