mirror of https://github.com/RolandWH/ceesort.git
40 lines
874 B
C
40 lines
874 B
C
/*
|
|
* Filename: bsrch.c
|
|
* Author(s): Roland (r.weirhowell@gmail.com)
|
|
* Description: Perform binary search on an integer array
|
|
* License: MIT (https://spdx.org/licenses/MIT.html)
|
|
*/
|
|
|
|
#include "bsrch.h"
|
|
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
|
|
|
|
int bsrch(int target, int* arr, int n)
|
|
{
|
|
// TODO: Find a way to error if list is out of order
|
|
int start = 0, end = n - 1;
|
|
if (arr[start] > target || arr[end] < target) return -1;
|
|
int mid = (start + end) / 2;
|
|
|
|
while (true)
|
|
{
|
|
if (arr[mid] == target) break;
|
|
if (start == end) return -1;
|
|
if (mid == end) return -1;
|
|
else if (arr[mid] < target)
|
|
{
|
|
start = mid + 1;
|
|
mid = (start + end) / 2;
|
|
}
|
|
else if (arr[mid] > target)
|
|
{
|
|
end = mid - 1;
|
|
mid = (start + end) / 2;
|
|
}
|
|
}
|
|
|
|
return mid;
|
|
}
|