二分查找

 

从基础学起

 

package b; public class Btest { /** * 二分法查找 */ public static void main(String[] args) { int[] nums={1,2,3,4,5,6,7,8,9};//已经排好序的数列 int maxSize = nums.length+1; int minSize = 0; int halfSize = 0; int halfNum = 0; int targetNum=6;//查找目标 while(true){ halfSize=(minSize+maxSize)/2; halfNum = nums[halfSize]; if(targetNum==halfNum){ System.out.println(targetNum+"is found his index is"+((minSize+maxSize)/2)); break; } if(targetNum>halfNum){//向右 minSize=halfNum; } if(targetNum<halfNum){//向左 maxSize=halfSize; } } } }