UVA 1149 Bin Packing 装箱(贪心)

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5+42;
int a[maxn];

template<class T>
inline void scan_d(T *ret)
{
char c;*ret=0;
while((c=getchar())<'0'||c>'9');
while(c>='0'&&c<='9') { *ret = *ret*10+(c-'0'); c = getchar();}
}

int main()
{
int T;  scan_d(&T);
while(T--){
int n,L; scan_d(&n); scan_d(&L);
for(int i = 0; i < n; i++) scan_d(a+i);
sort(a,a+n);
int i = 0,j = n-1;
int ans = n;

while(i<j){
if(a[i] <= L-a[j]){
i++; j--; ans--;
} else {
j--;
}

printf("%d\n",ans);
if(T)putchar('\n');
}
return 0;
}