c语言简单递归/非递归实现二分查找

#include <stdio.h>
#include <stdlib.h>
int binSearch1(int* a, int left, int right, int data)
{
int mid =0;
while (left<=right)
{
mid = (left + right) / 2;
if (data == a[mid])
{
return mid;
}
else if (data > a[mid])
{
left = mid + 1;
}
else
{
right = mid - 1;
}

}
return -1;
}
//递归实现
int binSearch2(int* a, int left, int right, int data)
{
int mid = (left + right) / 2;
int index = 0;
if (data == a[mid])//递归终止1
{
return mid;
}
if (left > right)//递归终止2
{
return -1;
}
if (data > a[mid])
{
index=binSearch2(a, mid+1 , right, data);
}
else
{
index=binSearch2(a, left, mid-1, data);
}
return index;
}
int main()
{
int a[] = { 1, 3, 5, 7, 12, 15, 17, 19 };
int len = sizeof(a) / sizeof(int);
int data = 19;
int index = binSearch2(a, 0, len-1, data);
printf("data=%d,index=%d\n", data,index);
getchar();
}