基本排序（冒泡，选择，插入，希尔）

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
void swap(int *a, int i, int j)
{
    int tmp = a[i];
    a[i] = a[j];
    a[j] = tmp;
}
void BubbleSort(int *a, int n)
{
    for (int i = 0; i < n - 1; ++i)
        for (int j = n - 1; j > i; --j)
            if (a[j] < a[j - 1])
                swap(a, j - 1, j);
}

void SelectSort(int *a, int n)
{
    int k;
    for (int i = 0; i < n - 1; ++i){
        k = i;
        for (int j = i + 1; j < n; ++j){
            if (a[j] < a[k]) k = j;
        }
        if (k != i) swap(a, k, i);
    }
}
void InsertSort(int *a, int n)
{
    int tmp, j;
    for (int i = 1; i < n; ++i){
        tmp = a[i];
        j = i - 1;
        while (j >= 0 && a[j] > tmp){
            a[j + 1] = a[j];
            --j;
        }
        a[j + 1] = tmp;
    }
}

void ShellSort(int *a, int n)
{
    int tmp, j;
    for (int inc = n / 2; inc > 0; inc /= 2)
        for (int i = inc; i < n; ++i){
            tmp = a[i];
            j = i - inc;
            while (j >= 0 && a[j]>tmp){
                a[j + inc] = a[j];
                j -= inc;
            }
            a[j + inc] = tmp;
        }
}

int main()
{
    srand(time(NULL));
    const int cnt = 10;
    int a[cnt];
    for (int i = 0; i < cnt; ++i)
        a[i] = rand() % 100;
    ShellSort(a, cnt);
    for (int i = 0; i < cnt; ++i)
        printf("%d\t", a[i]);
    printf("\n");
}