Data Structure Array: Sort elements by frequency

http://www.geeksforgeeks.org/sort-elements-by-frequency-set-2/

 1 #include <iostream>
 2 #include <vector>
 3 #include <algorithm>
 4 #include <queue>
 5 #include <stack>
 6 #include <string>
 7 #include <fstream>
 8 #include <map>
 9 using namespace std;
10 
11 void printarray(int arr[], int n) {
12     map<int, int> S;
13     for (int i = 0; i < n; i++) {
14         if (S.find(arr[i]) == S.end()) S[arr[i]] = 1;
15         else S[arr[i]]++;
16     }
17     map<int, vector<int> > T;
18     for (map<int, int>::iterator it = S.begin(); it != S.end(); it++) {
19         T[it->second].push_back(it->first);
20     }
21     for (map<int, vector<int> >::iterator it = T.end(); it != T.begin();) {
22         it--;
23         vector<int> tmp = it->second;
24         for (int j = 0; j < tmp.size(); j++) {
25             for (int k = 0; k < it->first; k++) cout << tmp[j] << " ";
26         }
27     }
28 }
29 
30 int main() {
31     int arr[11] = {2, 3, 2, 4, 5, 12, 2, 3, 3, 3, 12};
32     printarray(arr, 11);
33     return 0;
34 }

posted @ 2014-04-09 12:56 ying_vincent 阅读(261) 评论(0) 收藏举报

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