二分查找 冒泡

#include <stdlib.h>
#include <stdio.h>

//使用二分查找法前提，必须是一个已排序数组

void init_array(int a[], int n)
{
    int i;
    srand(time(NULL));
    for (i = 0; i < n; i++)
        a[i] = rand() % 100;
}
void show_array(int a[], int n)
{
    int i;
    for (i = 0; i < n; i++)
        printf("%d\n", a[i]);
}
void sort_array2(int a[],int n){
	int i,j,temp;
	for(i=0;i<n-1;i++){
		//for(j=i;j<n-1;j++){ //冒泡排序，每次排好的都放在后面，所以不能这么些。
		for(j=0;j<n-1-i;j++){
			if(a[j]>a[j+1]){
				temp =a[j];
				a[j] = a[j+1];
				a[j+1] = temp;
				
			}				
		}
	}
}

void sort_array(int a[], int n)
{
    int i, j, tmp;
    for (i = 0; i < n; i++)
        for (j = 1; j < n-i; j++)
            if (a[j-1] > a[j]) {
                tmp = a[j-1];
                a[j-1] = a[j];
                a[j] = tmp;
            }
}
//二分查找，两种实现，递归实现和循环实现
/*
int search_array(int a[], int n, int key)
{
   int l = 0, r = n, m;

   while(r >= l) {

       m = (l+r)/2;

       if (key == a[m])
           return m;
       else if (key > a[m])
           l = m+1;
       else if (key < a[m])
           r = m-1;
    }

   return -1;
}
*/
int search_array(int a[], int l, int r, int key)
{
    int m;

    if (l > r)
        return -1;
    
    m = (l+r)/2;

    if (key == a[m])
        return m;
    else if (key > a[m])
        search_array(a, m+1, r, key);
    else if (key < a[m])
        search_array(a, l, m-1, key);
}
int main(void)
{
    int a[100], b, res;
    init_array(a, 100);
    sort_array(a, 100);
    show_array(a, 100);
    scanf("%d", &b);
    //res = search_array(a, 100, b);
    res = search_array(a, 0, 100-1, b);
    if (res == -1)
        printf("un find\n");
    else
        printf("array %d item is %d\n", res, a[res]);

    return 0;
}