学步园

#include <stdio.h>

/*binsearch : find x in v[0] <= v[1] <= ... <= v[n-1] */
int binsearch(int x, int v[], int n){
	int low, high, mid;

	low = 0;
	high = n - 1;

	while ( low <= high ) {
		mid = (low + high) / 2;
		if(x < v[mid]){
			high = mid - 1;
		}
		else if(x > v[mid]){
			low = mid + 1;
		}
		else{ /*found match*/
			return mid;
		}
	}

	return -1;
}

int main(){
	int array[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
	int location;
	int number = 4;
	location = binsearch(number, array, 11);
	printf("%d\n", location);
	return 0;
}