#include<stdio.h>
void binsrch(int x, int *a, int n) {
    int i=0, j=n-1, k=0; 
    do{
        k=(i+j)/2;
        if(a[k] < x)
            i = k;
        else if (a[k] > x)
            j = k;
    }while(a[k]!=x && i<j);
    
    if (a[k]==x)
        printf("x is in the array\nPosition of x=%d is at index=%d\n",x,k);
    else
        printf("x is not in the array\n");
}

int main(){
    int a[] = {4,5,6,7,8,9,10};
    binsrch(7,a,sizeof(a)/sizeof(int));
    return 0;
}