radix_sort

 1 #include<Stdio.h>
 2 void radix_sort(int a[],int n);
 3 int main(){
 4     int a[100],n;
 5     int i;
 6     scanf("%d",&n);
 7     for( i=0; i<n; i++)
 8         scanf("%d",&a[i]);
 9     radix_sort(a,n);
10     for( i=0; i<n; i++){
11         printf("%d ",a[i]);
12     }
13     printf("\n");
14     return 0;
15 }
16 
17 void radix_sort(int a[],int n){
18    int count_a[10],sort_a[100];
19    int i,j,k=1;
20    int radix=10;
21    while(1){
22         for( i=0; i<radix; i++){
23             count_a[i] = 0;
24         }
25         for( i=0; i<n; i++){
26             count_a[(a[i]/k)%radix]++;//(a[i]/k)%radix求出最低位的数值
27         }
28         if(n == count_a[0])//结束条件是所有的数的余10都等于0时
29             break;
30         for( i=1; i<10; i++){
31             count_a[i] = count_a[i]+count_a[i-1];
32         }
33         for( i=n-1; i>=0; i--){
34             sort_a[count_a[(a[i]/k)%radix]-1] = a[i];//从末尾开始读数有利于数的稳定性
35             count_a[(a[i]/k)%radix]--;
36         }
37         for( i=0; i<n; i++){//更新排序
38             a[i] = sort_a[i];
39         }
40         k *= radix;
41         for( i=0; i<n; i++){
42             printf("%d ",sort_a[i]);
43         }
44         printf("\n");
45         printf("k=%d\n",k);
46    }
47 
48 }