（水题）洛谷

https://www.luogu.org/problemnew/show/P1478

没啥好说的……

居然还漏写一个等于号WA了一发。

#include<bits/stdc++.h>
using namespace std;
#define ll long long

int n,tn=0,s,a,b;
struct apple{
    int y;

    bool operator<(apple that){
        return y<that.y;
    }
}app[5005];

int main(){
    scanf("%d%d",&n,&s);
    scanf("%d%d",&a,&b);

    for(int i=0;i<n;i++){
        int tx,ty;
        scanf("%d%d",&tx,&ty);
        if(a+b>=tx){
            app[tn].y=ty;
            tn++;
        }
    }

    sort(app,app+tn);

    int cnt=0;
    for(int i=0;i<tn;i++){
        if(s>=app[i].y){
            s-=app[i].y;
            cnt++;
        }
        else{
            break;
        }
    }

    printf("%d
",cnt);

}