链接：https://leetcode.com/problems/roman-to-integer/#/description 难度：Easy 题目：13. Roman to Integer Given a roman numeral, convert it to an integer. Input is gu...

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Given a positive integer num, write a function which returns Trueif num is a perfect square else False.

最常规的思路是直接将数反转再对比，但实际上，我们只需要反转后半部分跟前半部分对比就可以了。两种情况，一是位数为偶数，直接对比，位数为奇数，大数除以10对比。...

Given a non-negative integer numRows, generate the first numRows of Pascal's triangle.

今天在开发中判断两个Integer值相等，Integer a = 3;Duixiang duixiang = new Duixiang();duixiang = DAO.getDuixiang();Integer b = duixiang.getB();System.out.print(a == b)...

class Solution {public: int reverse(int x) { int res = 0; while (x != 0) { int t = res * 10 + x % 10; if (t / 10 !=...

public class Solution { public int myAtoi(String str) { if (str.isEmpty()) return 0; int sign = 1, base = 0, i = 0, n = str.length(); ...

class Solution {public: string intToRoman(int num) { string res = ""; vector<int> val{1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1}...

class Solution {public: int romanToInt(string s) { int res = 0; unordered_map<char, int> m{{&#x27;I&#x27;, 1}, {&#x27;V&#x27;, 5}, {&#x27;X&#x27;, 10}, {&#x27;L&#x27;, 50}, {&#x27;C&#...