#include<stdio.h>
#include<assert.h> void display(int * a, int n)
{
for(int i = 0; i < n; i++)
{
printf("%d,",a[i]);
}
printf("\n");
} void swap(int * a, int * b)
{
int temp;
temp = *a;
*a = *b;
*b = temp;
} void bubble_sort(int * a, int n)
{
int i = 0;
int j ;
for(i = 0; i < n-1; i++ )
{
for( j = i; j <= n-1; j++ )
{
if(a[j] >= a[i])
{
swap(&(a[j]), &(a[i]));
}
}
} } int main()
{
int a[8] ={2, 1, 3, 4, 5, 7, 6, 8};
int num = sizeof(a)/sizeof(int);
printf("before_sort:");
display(a, num);
bubble_sort(a,num);
printf("after_sort:");
display(a, num);
return 0; }
改进后：
#include <stdio.h>
#include <time.h> //交换两个数据
void swap(int *a, int *b)
{
int temp;
temp = *a;
*a = *b;
*b = temp;
} //显示交换后的数组
void display_array( int a[], int n )
{
int i;
for( i = 0; i < n; i++ )
printf( "%d ", a[i] );
} //冒泡排序
void bubble_sort( int a[], int n )
{ int i ,j;
int flag = 1; //判断比较中是否发生了交换 1代表进行了交换
for(i = 0; i<n-1 && flag; i++ ) //flag的作用：若上次排序没有发生交换，就说明数组已经是有序
{ //这样做可以减少不必要的后续比较
flag = 0;
for(j = n -1; j >=i; j-- ) //第一次比较时 j是 0 ~ 7 第二次是 1 ~ 7
{
if(a[j] > a[j + 1])
{
swap(&(a[j]), &(a[j+1]));
flag = 1;
}
}
} } int main()
{
clock_t start, finish;
start = clock();
int n = 8;
int a[] = { 2, 1, 3, 4, 5, 7, 6, 8 };
printf( "Before sorting: " );
display_array( a, n );
bubble_sort( a, n );
printf( "After sorting: " );
display_array( a, n );
finish = clock();
printf("\n本次计算一共耗时: %f秒\n\n", (double)(finish-start)/CLOCKS_PER_SEC);
return 0;
}