K&R(3.3): Else-Ifs binearch Code

#include    "stdio.h"
 #define NELEMS(array) (sizeof(array) / sizeof(array[0]))

/* main: test for binary search */
int main(int argc, char *argv[])
{
    int i, imatch;
    i = 3;
    imatch = 0;
     int iv[] = {1, 2, 3, 4, 5};
     imatch = binsearch(i, iv, NELEMS(iv));
     printf("%d\n", imatch);
    return 0;
}

/* binsearch: find x in v[0] <= v[1] <= ... <= v[n-1] */
int binsearch (int x, int v[], int n)
{
    int low, high, mid;

    low = 0;
    high = n - 1;
    while (low <= high) {
        mid = (low+high)/2;
        if (x < v[mid])
          high = mid + 1;
        else if (x > v[mid])
          low = mid + 1;
        else /* found match */
          return mid;
    }
    return -1;
}