Submission #2998446

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Source Code Expand

#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
ll n, k, a[30010], b[30010];

bool judge(ll x){
    ll res = 0;
    for (ll i = 0; i < n; i++) {
        ll lb = -1, ub = n;
        while(lb + 1 < ub){
            ll mid = (lb + ub) / 2;
            if (a[mid] * b[i] <= x) lb = mid;
            else ub = mid;
        }
        res += lb + 1;
    }
    return res >= k;
}

int main(void){
    // Your code here!
    cin >> n >> k;
    for (ll i = 0; i < n; i++) cin >> a[i];
    for (ll i = 0; i < n; i++) cin >> b[i];
    sort(a, a + n); sort(b, b + n);
    ll lb = 0, ub = a[n - 1] * b[n - 1];
    while(lb + 1 < ub){
        ll mid = (lb + ub) / 2;
        if (judge(mid)) ub = mid;
        else lb = mid;
    }
    cout << ub << endl;
}

Submission Info

Judge Result