程序：在数组中用二分法找到相应的数字下标

#include<stdio.h>

int main()

{

int arr[] = { 1,2,3,4,5,6,7,8,9,10 };

int left = 0;

int right = sizeof(arr) / sizeof(arr[0]);

int mid = 0;

int answer = 8;

while (left <= right)

{

mid = (left + right) / 2;if (arr[mid] > answer)
  {
    right = mid - 1;
  }
  else if (arr[mid] < answer)
  {
    left = mid + 1;
  }
  else
  {   printf("找到了在%d", mid);
    break;
  }
}
if (right > left)
{
  printf("没有找到  ");
}
return 0;

if (arr[mid] > answer)
  {
    right = mid - 1;
  }
  else if (arr[mid] < answer)
  {
    left = mid + 1;
  }
  else
  {   printf("找到了在%d", mid);
    break;
  }
}
if (right > left)
{
  printf("没有找到  ");
}
return 0;
}