leetcode 704 题目链接:
https://leetcode.com/problems/binary-search/

尝试 c++ 写题,搭建架子代码(尝试搭建ACM格调)

class Solution{public:    int search(vector<int> &nums, int target)    {    }};int main(){    Solution sol;    vector<int> nums = {-1, 0, 3, 5, 9, 12};    sol.search({-1, 0, 3, 5, 9, 12}, 9);    // 十分量援用的初始值必须为左值    // initial value of reference to non-const must be an lvalue}

https://blog.csdn.net/hou09tian/article/details/80565343
这边文章解释的很分明了,十分量援用传参进去后可能会被批改,如果是个右值显然是不行的

再次运行报不能够初始化,原来vscode默认只反对c++98规范,在.vscode里的task.json增加”-std=c++11“编译参数即可

算法思路文章参考:
https://programmercarl.com/0704.%E4%BA%8C%E5%88%86%E6%9F%A5%E...

最终ac代码:(左闭右开)

#include <iostream>#include <vector>using namespace std;class Solution {public:    int search(vector<int>& nums, int target) {        size_t start = 0;        size_t end = nums.size();        while (start < end) {            size_t middle = start + ((end - start) >> 1);            if (nums[middle] == target) {                return static_cast<int>(middle);            } else if (nums[middle] > target) {                end = middle;            } else {                start = middle + 1;            }        }        return -1;    }};

再次尝试左闭右闭:

class Solution{public:    int search(vector<int> &nums, int target)    {        size_t start = 0;        size_t end = nums.size() - 1;        while (start <= end)        {            size_t middle = start + ((end - start + 1) >> 1);            if (nums[middle] == target)            {                return static_cast<int>(middle);            }            else if (nums[middle] > target)            {                end = middle - 1;            }            else            {                start = middle + 1;            }        }        return -1;    }};

[5], -5 的用例过不去,tle了,将size_t改为int,通过。
能够看出为什么api之类的都采纳左闭右开,写进去的代码更天然,计算区间什么的也更间接。

leetcode 27 题目链接:
https://leetcode.com/problems/remove-element/

ac代码:

class Solution{public:    int removeElement(vector<int> &nums, int val)    {        for (vector<int>::iterator it = nums.begin(); it != nums.end();)        {            if (*it == val)            {                it = nums.erase(it);// O(n) time complexity            }            else            {                it++;// prefer pre-increment for post-increment making a temporary copy            }        }        return nums.size();    }};