二分搜索没有给出正确的输出

Question

Getting wrong output of -1 and -1 it is going in the else section no compile time errors getting an output of -1

> Here the code is going out of the loop for all test cases how?I am unable to understand what is the mistake as I am new to programming

please help me I had asked a pretty similar question in linear search This is iterative approach tried even with recursive doesn't work.

int bin_search(int A[], int left, int right, int k)
{
    int found=0,mid;
    mid=(left+right)/2;
    if(right>=1)
    {
        if(k>A[left])
        {
            left=k;
            bin_search(A,mid+1,right,k);
        }
        else if(k<A[right])
        {
            right=k;
            bin_search(A,left,mid-1,k);
        }
        else if(A[mid]=k)
        {   
            return mid;
        }   

    }
   else return -1;
}
int main()
{int n;
 int A[]={1,2,3,4,5};
 int a=bin_search(A,0,n-1,4);
 printf("%d ",a);
}

Answer 1

Here's a correct code

 #include <iostream> using namespace std; int bin_search(int A[], int left, int right, int k) { int found=0,mid; mid=(left+right)/2; if(left <= right) { if(k>A[mid]) { left=mid+1; bin_search(A,mid+1,right,k); } else if(k<A[mid]) { right=mid-1; bin_search(A,left,mid-1,k); } else if(A[mid]=k) { return mid; } } else return -1; } int main() { int n = 5; int A[]={1,2,3,4,5}; int a=bin_search(A,0,n-1,2); printf("%d ",a); }