uva 1149:Bin Packing(贪心)

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

#define N 100100

int a[N];

int main() {
    int t;
    scanf("%d", &t);
    bool isfirst = true;
    while (t--) {
        if (isfirst) isfirst = false;
        else puts("");
        int n;
        scanf("%d", &n);
        int l;
        scanf("%d", &l);

        for (int i = 0; i < n; i++) {
            scanf("%d", &a[i]);
        }
        sort(a,a+n);

        int st = 0;
        int ed = n-1;
        int cnt = 0;
        while (st <= ed) {
            if (st != ed){
                if (a[st]+a[ed] <= l) {
                    st++;
                    ed--;
                    cnt++;
                } else {
                    ed--;
                    cnt++;
                }
            } else {
                cnt++;
                ed--;
            }
        }

        printf("%d\n", cnt);
    }
    return 0;
}