SRM 595 DIV1 250

挺简单的组合把。

 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <vector>
 using namespace std;
 #define LL long long
 int flag[];
 int p[];
 class LittleElephantAndIntervalsDiv1
 {
 public :
     LL getNumber(int M, vector <int> L, vector <int> R)
     {
         LL ans = ;
         int i,j;
         for(i = ;i < L.size();i ++)
         {
             for(j = L[i];j <= R[i];j ++)
             p[j] = i+;
         }
         for(i = ;i <= M;i ++)
         {
             if(p[i]&&!flag[p[i]])
             {
                 flag[p[i]] = ;
                 ans *= ;
             }
         }
         return ans;
     }
 };