在写C++程序之前必须要做的一个步骤就是包含各种头文件，但是随着代码量的增大这些头文件实在是记不住……而且Visual Studio又不像Java 的eclipse、IntelliJ IDEA这种可以智能补全（头发都要秃了），终于查阅资料后发现一个万能头文件——bits/stdc++.h，只要写上这个头文件，基本一切STL容器的函数都可以搞定！！

     可问题又来了……我用的编译器Visual Studio 2017里没有这个头文件怎么办，于是又有了一个新的想法。。只要将下列代码复制到文本文件，保存为stdc++.h，再放到VS2017的bits文件夹里，就没问题了：（在官网可以查找bits/stdc++.h头文件的内容）

// C++ includes used for precompiling -*- C++ -*-
// Copyright (C) 2003-2014 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 <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 <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

（然后新建一个名为bits的文件夹，将我们上面万能头文件的定义复制到该文件。保存在bits文件目录下即可。本人目录为D:\VS2017\VC\Tools\MSVC\14.16.27023\include\bits）