洛谷：U479672题解

好久没发题解了，今天来一道别人自创的题

#include <iostream>
#include <algorithm>
using namespace std;
const int MAX_M = 1e5 + 5;
int m;
long long n;
long long a[MAX_M];
bool canBuy(long long t) {
    long long total = 0;
    for (int i = 0; i < m; ++i) {
        if (t >= a[i]) {
            total += (t - a[i] + 1);
            if (total >= n) return true;
        }
    }
    return false;
}
int main() {
    cin >> n >> m;
    for (int i = 0; i < m; ++i) {
        cin >> a[i];
    }
	sort(a, a + m);
	long long left = 0;
    long long right = 1e18; 
    long long ans = right;
	while (left <= right) {
        long long mid = (left + right) / 2;
        if (canBuy(mid)) {
            ans = mid;
            right = mid - 1;
        } else {
            left = mid + 1;
        }
    }
    cout << ans;
    return 0;
}

好好干吧！