51Nod 1432 独木舟 （贪心）

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <vector>
 6 #include <cstdlib>
 7 #include <iomanip>
 8 #include <cmath>
 9 #include <ctime>
10 #include <map>
11 #include <set>
12 using namespace std;
13 #define lowbit(x) (x&(-x))
14 #define max(x,y) (x>y?x:y)
15 #define min(x,y) (x<y?x:y)
16 #define MAX 100000000000000000
17 #define MOD 1000000007
18 #define pi acos(-1.0)
19 #define ei exp(1)
20 #define PI 3.141592653589793238462
21 #define INF 0x3f3f3f3f3f
22 #define mem(a) (memset(a,0,sizeof(a)))
23 typedef long long ll;
24 const int N=10005;
25 const int mod=1e9+7;
26 int a[N];
27 int main()
28 {
29     int n;
30     ll m;
31     scanf("%d%lld",&n,&m);
32     for(int i=0;i<n;i++){
33         scanf("%d",&a[i]);
34     }
35     sort(a,a+n);
36     int s=0;
37     int i=0,j=n-1;
38     while(i<=j){
39         if(a[i]+a[j]<=m){
40             s++;
41             j--;
42             i++;
43         }
44         else {
45             j--;
46             s++;
47         }
48     }
49     printf("%d\n",s);
50     return 0;
51 }