基本功练习_2_27_之二分法查找

#include<stdio.h>
int search(int *a,int key,int low,int high)
{
 int mid;
 if(low>high)
 return -1;
 mid=(low+high)/2;
 if(a[mid]==key)return mid;
 else if(a[mid]>key)return search(a,key,low,mid-1);
 else return search(a,key,mid+1,high);
}
int main(void)
{
 int a[]={
  1,2,3,4,5,6,7,8,9,12,13,45,67,89,99,101,111,123,134,565,677
 };
 int i=search(a,99,0,sizeof(a)/sizeof(a[0])-1);
 printf("99是数组中第%d个数\n",i+1);
 return 0;
}