1 /**
2 * 排序算法之计数排序
3 **/
4 #include <iostream>
5 #include <vector>
6 using namespace std;
7
8 void CountSort(vector<int> &arr, int maxVal) {
9 int len = arr.size();
10 if (len < 1)
11 return;
12 vector<int> count(maxVal+1, 0);
13 vector<int> tmp(arr);
14 for (auto x : arr)
15 count[x]++;
16 for (int i = 1; i <= maxVal; ++i)
17 count[i] += count[i - 1];
18 for (int i = len - 1; i >= 0; --i) {
19 arr[count[tmp[i]] - 1] = tmp[i];
20 count[tmp[i]]--; //注意这里要减1
21 }
22 }
23
24 int main()
25 {
26 vector<int> arr = { 1,5,3,7,6,2,8,12,4,3,3 };
27 int maxVal = 12;
28 CountSort(arr,maxVal);
29 for (auto x : arr)
30 cout << x << " ";
31 cout << endl;
32 return 0;
33 }
