Submission #61607243

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Source Code Expand

#include <bits/stdc++.h>
using ll = long long;

const int N = 3e5;

void solve() {
    int n;
    std::cin >> n;
    std::vector<int> a(n + 1);
    for (int i = 1; i <= n; i++) {
        std::cin >> a[i];
    }
    ll cnt = 0;
    for (int i = 1; i <= n; i++) {
        cnt += a.end() - std::lower_bound(a.begin() + 1, a.end(), a[i] * 2);
    }
    std::cout << cnt;
}

int main() {
    std::ios::sync_with_stdio(0), std::cout.tie(0), std::cin.tie(0);
    int t;
    t = 1;
    while (t--) {
        solve();
    }
    return 0;
}

Submission Info

Judge Result