HDU 3177 Crixalis's Equipment （贪心+差排）

2

20 3
10 20
3 10
1 7

10 2
1 10
2 11

Yes
No

#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
struct S{
int a, b;
};
bool cmp(const S &s1, const S &s2){
if(s1.a + s2.b == s2.a + s1.b)
return s1.b < s2.b;
return s1.a + s2.b < s2.a + s1.b;
//return s1.b - s1.a > s2.b - s2.a;	也可
}
int main(){
S s;
vector<S> vec;
int t, v, n, flag;
scanf("%d", &t);
while(t--){
flag = 0;
scanf("%d%d", &v, &n);
while(n--){
scanf("%d%d", &s.a, &s.b);
vec.push_back(s);
}
sort(vec.begin(), vec.end(), cmp);
for(vector<S>::iterator it = vec.begin(); it != vec.end(); ++it){
if(v >= (*it).b && v >= (*it).a){
v -= (*it).a;
}else{
flag = 1;
break;
}
}
if(flag)
printf("No\n");
else
printf("Yes\n");
vec.clear();
}
return 0;
}