題目描述

題目解答

import java.util.ArrayList;
public class Solution {
    public int minNumberInRotateArray(int [] array) {
        if(array==null || array.length==0){
            
 
return 0;
        }
        int low=0,high=array.length-1;
        while(low<high){
            int mid=low+(high-low)/2;
            if(array[mid]>array[high]){ //[3,4,5,6,0,1,2]，最小數字一定在mid右邊
                low=mid+1;
            }else if(array[mid]==array[high]){ // [1,0,1,1,1] 或者[1,1,1,0,1] ,最小數字不好判斷在mid左邊還是右邊
 

                high=high-1;
            }else{ //[2,2,3,4,5,6,6]，最小數字一定在mid或者mid的左邊
                high=mid; 
            }
        }
        return array[low];
    }
}

二分法