topcode SRM 577 DIV2 EllysRoomAssignmentsDiv2

很郁闷的一题，一定要认真读题目，特别注意这句话 Concatenate its elements to obtain one long string，，，一定要理解这句话

 1 #include <iostream>
 2 #include <string>
 3 #include <vector>
 4 #include <algorithm>
 5 #include <sstream>
 6 #include <numeric>
 7 using namespace std;
 8 
 9 class EllysRoomAssignmentsDiv2{
10 public:
11     double getProbability(vector <string> ratings){
12         string split="";
13         string all = accumulate(ratings.begin(),ratings.end(),split);
14         stringstream sst(all);
15         vector<int> score;
16         int tmp;
17         while(sst >> tmp) score.push_back(tmp);
18         int score_elly = score[0];
19         sort(score.begin(),score.end(),greater<int>());
20         int cnt_elly = 0;
21         for(int i = 0 ; i < score.size(); i ++  ){
22             if( score[i] == score_elly) {
23                 cnt_elly = i;break;
24             }
25         }
26         int R = score.size()%20 ? score.size()/20+1 : score.size()/20;
27         if(R <= 1 || cnt_elly == 0 ) return 1.0;
28         else if( cnt_elly < R ) return 0.0;
29         else return 1.0/R;
30 
31     }
32 };