80分qwq

代码如下：

#include <iostream>
#include <algorithm>
using namespace std;
int m, w[20005], n, ans, l = 1, r;
bool cmp(int a, int b){
	return a > b;
}
int main(){
	cin >> m >> n;
	for(int i = 1; i <= n; i++) cin >> w[i];
	r = n;
	sort(w + 1, w + n + 1, cmp);
	while(true){
		if(l == r){
			ans++;
			break;
		}
		if(l > r) break;
		if(w[l] + w[r] > m){
			if(w[l] <= w[r]){
				ans++;
				r--;
			} else {
				ans++;
				l++;
			}
		} else {
			ans++;
			l++;
			r--;
		}
	}
	cout << ans << endl;
    return 0;
}