二分查找

二分查找

#include<stdio.h>
#include<stdlib.h>

typedef struct node {
	int element[10];
	int length;
}Lel;
//二分查找
int Lbinary(Lel L, int K) {	//K为设置的哨兵
	int left, mid, right;	
	left = 0;
	right = L.length;
	while (left <= right) {			
		mid = (left + right) / 2;	
		if (L.element[mid] > K)		right = mid - 1;
		else if (L.element[mid] < K)	left = mid + 1;
		else return mid;
	}
	return -1;
}

int main() {
	Lel L = { 1,2,3,4,5,6,7,8,9,10,9 };
	int a;
	a = Lbinary(L, 6);
	printf("%d",a);
	system("pause");
	return 0;
}