基数排序

#include <bits/stdc++.h>
using namespace std;
const int maxn=1e7+10;
int n,a[maxn];
int maxbit(int data[], int n) //辅助函数，求数据的最大位数
{
    int maxData = data[0];
    for (int i = 1; i < n; ++i)
    {
        if (maxData < data[i])
            maxData = data[i];
    }
    int d = 1;
    int p = 10;
    while (maxData >= p)
    {
        maxData /= 10;
        ++d;
    }
    return d;
}
void radixsort(int data[], int n) //基数排序
{
    int d = maxbit(data, n);
    int *tmp = new int[n];
    int *count = new int[10]; //计数器
    int i, j, k;
    int radix = 1;
    for (i = 1; i <= d; i++) //进行d次排序
    {
        for (j = 0; j < 10; j++)
            count[j] = 0; //每次分配前清空计数器
        for (j = 0; j < n; j++) {
            k = (data[j] / radix) % 10; //统计每个桶中的记录数
            count[k]++;
        }
        for (j = 1; j < 10; j++)
            count[j] = count[j - 1] + count[j]; //将tmp中的位置依次分配给每个桶
        for (j = n - 1; j >= 0; j--) //将所有桶中记录依次收集到tmp中
        {
            k = (data[j] / radix) % 10;
            tmp[count[k] - 1] = data[j];
            count[k]--;
        }
        for (j = 0; j < n; j++) //将临时数组的内容复制到data中
            data[j] = tmp[j];
        radix = radix * 10;
    }
    delete[]tmp;
    delete[]count;
}
int main() {
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    radixsort(a, n);
    for (int i = 0; i < n; i++) {
        printf("%d ", a[i]);
    }
}