[C++知识库]二分法举例

#include<stdio.h>
#define?? ?M 10
int main()
{
?? ?int a[M] = { -12,0,6,16,23,56,80,100,110,115 };
?? ?int n,low, mid, high, find;
?? ?low = 0;
?? ?high = M - 1;
?? ?find = 0;
?? ?printf("please input number:\n");
?? ?scanf_s("%d",&n);
?? ?while (low <= high)
?? ?{
?? ??? ?mid = (low + high) / 2;
?? ??? ?if (n == a[mid])
?? ??? ?{
?? ??? ??? ?find = 1;
?? ??? ??? ?break;
?? ??? ?}
?? ??? ?else if (n > a[mid])
?? ??? ??? ?low = mid + 1;
?? ??? ?else
?? ??? ??? ?high = mid - 1;
?? ?}
?? ?if (find == 1)
?? ??? ?printf("The index of %d is %d", n, mid);
?? ?else
?? ??? ?printf("These is not %d",n);

}