•<bits/stdc++.h>介紹

　　 #include<bits/stdc++.h>  包含了目前 C++ 所包含的所有標頭檔案，又稱萬能標頭檔案，簡直是開掛一般的存在。

　　你程式設計所需要的標頭檔案基本上都囊括在了該萬能標頭檔案中，試想一下，將若干行標頭檔案：

#include<iostream>
#include<cstdio>
#include<string>
#include<map>
#include<vector>
......

　　只用一行程式碼  #include<bits/stdc++.h>

 來代替，是不是簡單粗暴！

•如何在VS2022中使用萬能頭

　　可惜，這麼好的萬能頭，在VS2022中不能使用，難道就此放棄嗎？

　　不，作為21世紀有思想的時代青年，這點問題怎麼能難道我呢？

　　首先，找到你本地VS的安裝目錄，在VS中找到  include  資料夾，我的在該路徑上：

 D:\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.31.31103\include 

　　在  include  資料夾下建立一個  bits  資料夾，並新建一個  stdc++.h 的檔案，將如下程式碼複製到  stdc++.h  檔案中，即可在 VS2022 中使用萬能頭。

// C++ includes used for precompiling -*- C++ -*-

// Copyright (C) 2003-2016 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
 
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file stdc++.h
 *  This is an implementation file for a precompiled header.
 */

// 17.4.1.2 Headers

// C
#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdalign>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cuchar>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <codecvt>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

#if __cplusplus >= 201402L
#include <shared_mutex>
#endif

　　設定完成後，重啟 VS 即可愉悅的使用萬能頭了，完結撒花！