binary_search.c

#include <stdio.h>

int main(void){
  // Binary search
  // given a target and a sorted array
  // find the midpoint of the current array
  // if midpoint value is target return
  // decide which half holds the target value
  // repeat the steps with the subarray to the right or left of the current midpoint

  int array[] = {2,4,6,8,10,12,14,16,18};
  int length = sizeof array/sizeof array[0];

  int start = 0;
  int end = length-1;
  int mid = (start + end) / 2;

  int target = 2;

  while(start <= end){
    if (array[mid] == target){
      printf("mid was target at position: %i\n", mid);
      break;
    }

    if(target < array[mid]){
      end = mid-1;
      mid = (start + end) / 2;
    }
    else{
      start = mid + 1;
      mid = (start + end) / 2;
    }
      
  }

  return 0;
}