# 演算法題 - Binary Search - Leetcode - by PeterWang
## 題目資訊 Leetcode 704
###### tags: `Binary Search` `Leetcode`
## Binary Search概述
以下面程式碼為例，把搜尋的範圍不斷縮小，可以減少搜尋時間。

## 程式碼

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int maxn=nums.size()-1;
        int minn=0;
        int mid=(maxn+minn)/2;
        while(maxn!=minn){
            mid=(maxn+minn)/2;
            if(nums[mid]>=target){
                maxn=mid;
            }
            else{
                minn=mid+1;
            }
        }
        if(nums[maxn]==target){
            return maxn;
        }
        else{
            return -1;
        }
    }
};

## 資料來源
[leetcode](https://leetcode.com/)
[題目敘述](https://leetcode.com/problems/binary-search/)

## 備註
>[name=PeterWang]
>[time=Mon, Jun 14, 2021 11:29 AM]