codeingdog的专栏

【题目】给你一个整数数组 nums，请你返回该数组中恰有四个因数的这些整数的各因数之和。如果数组中不存在满足题意的整数，则返回 0 。示例：输入：nums = [21,4,7]输出：32解释：21 有 4 个因数：1, 3, 7, 214 有 3 个因数：1, 2, 47 有 2 个因数：1, 7答案仅为 21 的所有因数的和。提示：1 <= n...

Given an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution, and you may not use the same ...

Determine whether an integer is a palindrome. An integerisapalindrome when itreads the same backward as forward.Example 1:Input: 121Output: trueExample 2:Input: -121Output: falseExpl...