Data Structure Array: Given an array of of size n and a number k, find all elements that appear more than n/k times

http://www.geeksforgeeks.org/given-an-array-of-of-size-n-finds-all-the-elements-that-appear-more-than-nk-times/

这一题如果没空间要求就没那么麻烦了

 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 more(int arr[], int n, int k) {

12     map<int, int> S;

13     for (int i = 0; i < n; i++) {

14         if (S.find(arr[i]) != S.end()) S[arr[i]]++;

15         else if (S.size() == k) {

16             for (map<int, int>::iterator it = S.begin(); it != S.end(); it++) {

17                 if (it->second == 1) S.erase(it->first);

18                 else it->second--;

19             }

20         }

21         else S[arr[i]] = 1;

22     }

23     for (map<int, int>::iterator it = S.begin(); it != S.end(); it++) {

24         int tmp = 0;

25         for (int i = 0; i < n; i++) {

26             if (arr[i] == it->first) tmp++;

27         }

28         if (tmp > n / k) cout << it->first << " ";

29     }

30 }

31 

32 int main() {

33     int arr[7] = {4, 5, 6, 7, 8, 4, 4};

34     more(arr, 7, 3);

35     return 0;

36 }