#include <stdio.h>
#include <stdlib.h>
void printArray(int arr[], int n);
int getMax(int arr[], int n) {
int max = arr[0];
for (int i = 1; i < n; i++) {
if (arr[i] > max) {
max = arr[i];
}
}
return max;
}
void countingSort(int arr[], int n, int exp) {
const int RADIX = 10;
int* output = (int*)malloc(n * sizeof(int));
int count[RADIX];
for (int i = 0; i < RADIX; i++) {
count[i] = 0;
}
for (int i = 0; i < n; i++) {
count[(arr[i] / exp) % RADIX]++;
}
for (int i = 1; i < RADIX; i++) {
count[i] += count[i - 1];
}
for (int i = n - 1; i >= 0; i--) {
output[count[(arr[i] / exp) % RADIX] - 1] = arr[i];
count[(arr[i] / exp) % RADIX]--;
}
for (int i = 0; i < n; i++) {
arr[i] = output[i];
}
free(output);
}
void radixSort(int arr[], int n) {
int max = getMax(arr, n);
for (int exp = 1; max / exp > 0; exp *= 10) {
countingSort(arr, n, exp);
}
}
int main() {
int arr[] = {37, 123, 777, 11, 2, 17, 93, 23};
int n = sizeof(arr) / sizeof(arr[0]);
printf("排序前: ");
printArray(arr, n);
radixSort(arr, n);
printf("排序后: ");
printArray(arr, n);
return 0;
}
void printArray(int arr[], int n) {
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
}