基数排序

#include <stdio.h>  
#define NUM 10  //数组元素个数  
  
  
void counting_sort(int a[],int b[],int c[],int atemp[]);  
int main()  
{  
    int i;  
    int j;  
  
    int a[10] = {326,54,512,13,9,71,92,61,53,19}; //input array  
    int atemp[10];  
    int b[10]; //output array  
    int c[10]; //temp all element are not biger than 10  
      
    // 个位排序  
    for (i = 0;i < NUM;i++)   
        atemp[i] = a[i] % 10;  
    counting_sort(atemp,b,c,a);  
    for (i = 0;i < NUM;i++)  
        a[i] = b[i];  
  
    // 十位排序  
    for (i = 0;i < NUM;i++)   
        atemp[i] = a[i] / 10 % 10;  
    counting_sort(atemp,b,c,a);  
    for (i = 0;i < NUM;i++)  
        a[i] = b[i];  
    //百位排序  
    for (i = 0;i < NUM;i++)  
        atemp[i] = a[i] / 100 % 10;  
    counting_sort(atemp,b,c,a);  
          
    for (i = 0;i < NUM;i++)  
        printf(" %d ",b[i]);  
    printf("\n");  
      
      
}  
//计数排序算法，a为待排序数组(一位数，要和atemp区分开)，b为排序好的数组,c为中间数组，atemp为原始数组(包括三位数)  
void counting_sort(int a[],int b[],int c[],int atemp[])  
{  
    int i,j;  
    for (i = 0;i < NUM;i++)  
        c[i] = 0;  
    for (j = 0;j < NUM;j++)  
        c[a[j]] += 1;  
    for (i = 1;i < NUM;i++)  
        c[i] = c[i] + c[i-1];  
    for (j = 9;j >= 0;j--) {  
        b[c[a[j]] - 1] = atemp[j];  
        c[a[j]] -= 1;  
    }  
}