Submission #2978420

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Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef long long ll;

int main(){
    int n,k;
    cin >> n >> k;
    vector<ll> a(n), b(n);
    for(int i=0;i<n;i++) cin >> a[i];
    for(int i=0;i<n;i++) cin >> b[i];
    sort(a.begin(), a.end());
    sort(b.begin(), b.end());

    ll ng = a[0] * b[0], ok = a[n-1] * b[n-1] + 1LL;
    while(ok - ng > 1LL){
        ll mid = (ok+ng) / 2LL;
        int k_tmp = 0;
        for(int i=0;i<n;i++){
            if(a[i] > mid) break;
            k_tmp += int(upper_bound(b.begin(), b.end(), mid/a[i]) - b.begin());
        }

        if(k_tmp >= k){
            ok = mid;
        }else{
            ng = mid;
        }
    }
    cout << ok << endl;
}

Submission Info

Judge Result