D.little w and Exchange(思维）

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/wwwlps/article/details/85930694

题目链接：https://ac.nowcoder.com/acm/contest/297/D

#include<iostream>
#include<cstring>
#include<string>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<queue>
#include<vector>
#include<set>
#include<map>
#include<ctime>
typedef long long int ll;
using namespace std;
const double INF=1e8;
const double eps=0.0001;
const double pi=acos(-1.0);
const int inf = 0x3f3f3f3f;
const int maxn = 100005;
const ll mod = 998244353;
 
ll n,m;
ll a[maxn];
ll k;
int main(){
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        cin>>a[i];
    k = 0;
    sort(a+1, a+n+1);
    int flag = 1;
    for(int i=1; i<=n; i++)
    if(a[i] <= k+1){
        k += a[i];
    }
    else{
        flag = 0;
        break;
    }
    if(k >= m)
        cout<<"YES"<<endl;
    else
        cout<<"NO"<<endl;
    return 0;
}