PAT1048

注意一个坑，就是当M是偶数的时候可能有两个M >> 1的值，这种时候就只能数数了..

 1 #include <iostream>
 2 #include <vector>
 3 #include <string>
 4 #include <fstream>
 5
 6 using namespace std;
 7
 8 #define OJ
 9
10 #ifdef OJ
11 #define fin cin
12 #else
13 ifstream fin("in.data");
14 #endif
15
16 int main(){
17     int N, M, n;
18     fin >> N >> M;
19
20     vector<int> money(1001, 0);
21     for (int i = 0; i < N; i++){
22         fin >> n;
23         if (n >= M) continue;
24         money[n]++;
25     }
26
27     int half_M = (M >> 1) + 1;
28     for (int i = 1; i < half_M; i++){
29         if (money[i] > 0)
30             money[i]--;
31         else
32             continue;
33         if (money[M - i] > 0){
34             cout << i << " " << M - i << endl;
35             return 0;
36         }
37     }
38
39     cout << "No Solution" << endl;
40
41     return 0;
42 }