exam6_2.java

来自「基本的数据结构的java代码」· Java 代码 · 共 26 行

public class Exam6_2{
	public static int bSearch(int[] a, int x, int low, int high){
		int mid;
		
		if(low > high) return -1;
		
		mid = (low + high) / 2;
		if(x == a[mid]) return mid;
		else if(x < a[mid])
			return bSearch(a, x, low, mid - 1);
		else
			return bSearch(a, x, mid + 1, high);
	}
	
	public static void main(String[] args){
		int[] a = {1, 3, 4, 5, 17, 18, 31, 33};
		int x = 17;
		int bn;
		
		bn = bSearch(a, x, 0, 7);
		if(bn == -1) 
			System.out.println("x不在数组a中");
		else
			System.out.println("x在数组a中，下标为" + bn);		
	}
}