Binary Search

bsearch.c

#include <stdio.h>

int bsearch(int *a, int n, int v)
{
  int l = 0, r = n - 1, m = 0;

  while (l <= r) {
    m = l + ((r - l) >> 1);
    if (a[m] > v) {
      r = m - 1;
    } else if (a[m] < v) {
      l = m + 1;
    } else {
      return m;
    }
  }
  return -1;
}

int main(int argc, char **argv)
{
  int data[100];
  int i = 0, index = -1;
  for (;i < 100; i++) {
    data[i] = i + 10;
  }
  index = bsearch(data, 100, 44);
  printf("Find index = %d value = %d\n", index, data[index]);
  return 0;
}