153. Find Minimum in Rotated Sorted Array

先问了Hash, what happen if there is a collision?

public class Solution {
    public int findMin(int[] nums) {
        if(nums==null||nums.length==0) return 0;
        if(nums.length==1) return nums[0];
        int start=0,end=nums.length-1;
        while(start<end){
            int mid=(start+end)/2;
            if(mid>0&&nums[mid]<nums[mid-1]) return nums[mid];
            else if(nums[mid]>=nums[start]&&nums[mid]>nums[end]) start=mid+1;
            else end=mid-1;;
        }
        return nums[start];
    }
}