排序算法——C、C++混合编程实现

选择排序（O(m*n)）

//简单选择排序
#include<cstdio>
int main(int argc, char const *argv[])
{
  int A[6] ={0, 5, 2, 4, 2, 1};
  int n = 5;
  for (int i = 1; i <= n; ++i)    //进行n趟操作
  {
    int k = i;
    for (int j = i; j <= n; ++j)  //选出[i,n]中最小的元素，下标为k
    {
      if(A[j] < A[k]){
        k = j;
      }
    }
    int temp = A[i];        //交换A[k]与A[i]
    A[i] = A[k];
    A[k] = temp;
  }

  for (int i = 1; i <= n; ++i)
  {
    printf("%d ",A[i]);
  }
  printf("\n");
  return 0;
}

插入排序(O(m+n))

//直接插入排序
#include<cstdio>
int main(int argc, char const *argv[])
{
  int A[6] ={0, 5, 2, 4, 2, 1};
  int n = 5;
  for (int i = 1; i <= n; ++i)
  {
    int temp = A[i],j = i;
    while(j > 1 && temp < A[j - 1]){
      A[j] = A[j - 1];
      j--;
    }
    A[j] = temp;
  }

  for (int i = 1; i <= n; ++i)
  {
    printf("%d ",A[i]);
  }
  printf("\n");
  return 0;
}

交换排序（O(n^2)）

//冒泡排序
#include<cstdio>
int main(int argc, char const *argv[])
{
  int A[10] ={5, 2, 4, 2, 1};
  int n = 5;
  for (int i = 1; i <= n - 1; ++i)//进行n-1趟
  {
    for (int j = 0; j < 5 - i; ++j)//第i趟从a[1]到a[n - i - 1]都与下一个数进行比较
    {
      if(A[j] > A[j + 1]){//如果左边数更大，就交换位置
        int temp = A[j];
        A[j] = A[j + 1];
        A[j + 1] = temp;
      }
    }
  }

  for (int i = 0; i < n; ++i)
  {
    printf("%d ",A[i]);
  }
  printf("\n");
  return 0;
}