折半查找的迭代与递归实现

//以此纪念2013年12月18日在百度面试失败,其中写出了二分法的迭代查找却没写出递归查找
#include <stdio.h>
#define LEN 10

int bin_search(int array[], int low, int high, int key);//迭代
int bin_search2(int array[], int low, int high, int key);//递归

int main(){
int arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int key1 = 9,key2 = 3;

printf("key1的位置是 %d\n", bin_search(arr, 0, LEN-1, key1));
printf("key2的位置是 %d\n", bin_search2(arr, 0, LEN-1, key2));
return 0;
}

int bin_search(int array[], int low, int high, int key)
{
int m;
while(low<high){
m = (low + high)/2;
if(array[m]==key){
return m;
}elseif(array[m]>key){
low = m-1;
}else{
high = m+1;
}
}
return -1;
}
int bin_search2(int array[], int low, int high, int key)
{
int m = (low+high)/2;
if(low>high){
return -1;
}
if(array[m]==key){
return m;
}elseif(array[m]>key){
return bin_search2(array, low, m-1, key);
}else{
return bin_search2(array, m+1, high, key);
}
}