问题描述：
Given scores of N athletes, find their relative ranks and the people with the top three highest scores, who will be awarded medals: "Gold Medal", "Silver Medal" and "Bronze Medal".
Note:
N is a positive integer and won't exceed 10,000.All the scores of athletes are guaranteed to be unique.示例：
Input: [5, 4, 3, 2, 1] Output: ["Gold Medal", "Silver Medal", "Bronze Medal", "4", "5"] Explanation: The first three athletes got the top three highest scores, so they got "Gold Medal", "Silver Medal" and "Bronze Medal". For the left two athletes, you just need to output their relative ranks according to their scores. 问题分析：利用hashtable求解即可，过程详见代码：
class Solution { public: vector<string> findRelativeRanks(vector<int>& nums) { vector<int> nums2 = nums; sort(nums.begin(),nums.end()); map<int,int> m; vector<string> res; for(int i = nums.size() - 1,j = 1;i >= 0 ; i--) { m.insert(pair<int,int>(nums[i],j++)); } for(int i = 0; i < nums2.size(); i++) { if(m[nums2[i]] == 1) res.push_back("Gold Medal"); else if(m[nums2[i]] == 2) res.push_back("Silver Medal"); else if(m[nums2[i]] == 3) res.push_back("Bronze Medal"); else res.push_back(to_string(m[nums2[i]])); // c++ 11支持 } return res; } };