SRM 595 DIV1 250

挺简单的组合把。
 1 #include <cstdio>
 2 #include <cstring>
 3 #include <iostream>
 4 #include <vector>
 5 using namespace std;
 6 #define LL long long
 7 int flag[1001];
 8 int p[1001];
 9 class LittleElephantAndIntervalsDiv1
10 {
11 public :
12     LL getNumber(int M, vector <int> L, vector <int> R)
13     {
14         LL ans = 1;
15         int i,j;
16         for(i = 0;i < L.size();i ++)
17         {
18             for(j = L[i];j <= R[i];j ++)
19             p[j] = i+1;
20         }
21         for(i = 1;i <= M;i ++)
22         {
23             if(p[i]&&!flag[p[i]])
24             {
25                 flag[p[i]] = 1;
26                 ans *= 2;
27             }
28         }
29         return ans;
30     }
31 };