tortoise

1 不跟踪文件、文件夹 1.2 commit 时忽略 non-versioned 文件、文件夹 （3）在 global-ignores 行尾添加 *.dll （忽略文件 dll 类型文件，* 前面要有一个空格），*bin （忽略 bin 文件夹，* 前面要有一个空格），类型可以忽略其他后缀文件、文件夹 原文：https://www.cnblogs.com/850391642c/p/9319352.html

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, find the duplicate one. Example 1: Input: [1,3,4,2,2] Output: 2 Example 2: Input: [3,1,3,4,2] Output: 3 Note: You must not modify the array (assume the array is read only). You must use only constant, O (1) extra space. Your runtime complexity should be less than O ( n 2). There is only one duplicate number in the array, but it could be repeated more than once. class Solution { public int