经典二分查找问题

public class Solution {
/**
* @param nums: An integer array sorted in ascending order
* @param target: An integer
* @return an integer
*/
public int findPosition(int[] nums, int target) {
// Write your code here
if(nums==null||nums.length==0){
return -1;
}
int low=0;
int high=nums.length-1;
int mid=0;
while(low<=high){
mid=(high+low)/2;
if(nums[mid]>target){
high=mid-1;
}else if(nums[mid]<target){
low=mid+1;
}else{
return mid;
}
}
return -1;
}
}