hdu 6216 A Cubic number and A Cubic Number[数学] 题意:判断一个素数是否是两个立方数之差,就是验差分.. 题解:只有相邻两立方数之差才可能,,因为x^3-y^3=(x-y)(x^2+xy+y^2),看(x-y),就能很快想到不相邻的立方数之差是不可能是素数的:),,然后把y=x+1代入,得:p=3x^2+3x+1,所以可得判断条件为:①p-1必须能被3整除:②(p-1)/3必须能表示为两个相邻整数之积. #include<iostream> #inc…

A Cubic number and A Cubic Number Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others) Total Submission(s): 4947    Accepted Submission(s): 1346 Problem Description A cubic number is the result of using a whole number i…

Use map() and Number() to convert to number if possilbe or NaN. var str = ["1","1.23","3","4.0","five", undefined, .00]; var num = str.map( (s) => { return Number(s); }); console.log(num); //[1, 1.23, 3…

一.Ugly Number Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7. Not…

263. Ugly Number 注意:1.小于等于0都不属于丑数 2.while循环的判断不是num >= 0, 而是能被2 .3.5整除,即能被整除才去除这些数 class Solution { public: bool isUgly(int num) { ) return false; == ) num /= ; == ) num /= ; == ) num /= ; ? true : false; } }; 264. Ugly Number II 用一个数组去存第n个前面的所有整数,然后…

136. Single Number 除了一个数字,其他数字都出现了两遍. 用亦或解决,亦或的特点:1.相同的数结果为0,不同的数结果为1 2.与自己亦或为0,与0亦或为原来的数 class Solution { public: int singleNumber(vector<int>& nums) { if(nums.empty()) ; ; ;i < nums.size();i++) res ^= nums[i]; return res; } }; 137. Single N…

java.sql.SQLException: Io 异常: Invalid number format for port number   jdbc数据库链接配置没有写端口号 ​ 要检查jdbc的配置是否正确.…

报错信息: Caused by: java.sql.SQLException: Io 异常: Invalid number format for port number    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)    …

a number of 和the number of用法 1.   A number of + 複數名詞 + 複數動詞           =some/或a lot of + 複數名詞 + 複數動詞 2. The  number of + 複數名詞 + 單數動詞          = the amount of =總數 3.例如                          The number of cars is increasing.                      (汽車的…

Problem Description A cubic number is the result of using a whole number in a multiplication three times. For example, 3×3×3=27 so 27 is a cubic number. The first few cubic numbers are 1,8,27,64 and 125 . Given an prime number p . Check that if p is…