使用函数进行二分查找

#include <stdio.h>
#include <stdlib.h>
//定义二分查找函数
int searchArray(int arr[], int size, int to_find) {
//确定待查找区间[left, right]
	int left = 0;
	int right = size - 1;
	int mid;
	while (left <= right) {
	//二分数组
		mid = (left + right) / 2;
		if (to_find < arr[mid]) {
			right = mid - 1;
		}
		else if (to_find > arr[mid]) {
			left = mid + 1;
		}
		else {
			//此处可以返回待查找的数为arr[mid];
			return arr[mid];
		}
	}
	//数组不包含待查找数
	return -1;
}
int main() {
	int a[9] = { 1, 2 ,3, 4, 5, 6, 7, 8, 9 };
	printf("%d\n", searchArray(a, 9, 5));
	system("pause");
	return 0;
}