【測試技術打卡】第4天：leetcode刷題+linux命令打卡+mysql打卡

leetcode

1431. 擁有最多糖果的孩子

class Solution {
public:
    vector<bool> kidsWithCandies(vector<int>& candies, int extraCandies) {
        int n = candies.size();
        int max = *max_element(candies.begin(),candies.end());
        vector<bool> res ;
        for(int i=0;i<n;i++){
            if(candies[i]+extraCandies>=max){
                res.push_back(true);
            }else{
                res.push_back(false);
            }
        }
        return res;
    }
};

905. 按奇偶排序數組

class Solution {
public:
    vector<int> sortArrayByParity(vector<int>& A) {
        int len = A.size();
        int left =0;
        int right = len-1;

        while(left<right){
            while(A[left]%2==0 && left<right){
                left++;
            }
            while(A[right]%2!=0 && left<right){
                right--;
            }
            swap(A[left],A[right]);
        }
        return A;
    }
};

linux

cd

cd ..
cd ../..
cd ~
cd .

mysql

alter

alter table istester add column istester6 VARCHAR(100) NOT NULL;
desc istester;
alter table istester drop istester6;
desc istester;

insert

insert into istester(id,uname,idoxu) values(1,"idoxu",2020);
insert into istester(id,uname,idoxu) values(2,"idoxu2",2020);
insert into istester(id,uname,sex) values(11,"idoxu3",1),(12,"idoxu4",2),(13,"idoxu5",1),(14,"idoxu6",2);

insert into idoxu(id,stu_id,c_name,grade) values(4,11,"idoxu",90),(5,12,"lin",100),(6,33,"istester",20);

where

select * from istester where id = 1;
select * from idoxu where grade = 100;

select 包含

select * from idoxu where c_name like '%i%';
select * from istester where id like '%1%';
select * from istester where id like '%1%' order by id desc;
select * from istester where id like '%1%' order by id desc;

where in

select c_name,grade as "maxvalue" from idoxu where grade in (select max(grade) from idoxu);
select c_name,grade as "minvalue" from idoxu where grade in (select min(grade) from idoxu);

null < >

select * from istester where sex is null;
update istester set sex = 0 where sex is null;
select * from idoxu where grade < 60;
update idoxu set grade = 59 where grade < 60;

desc

select * from istester order by id desc;
select * from idoxu order by grade;