Automatic pre-compiler for submitting tasks on Codeforces

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Hello!

After seeing the recent hype towards debugging utils and code snippets usage and what not, and due to the fact that I had 30 minutes of free time to spend this afternoon, I decided to write a small Python script that pre-compiles multiple files into one big file for Codeforces submission.

The tool is here: https://pastebin.com/CR0mJXbR (Python 3 required)

Basically the tool does these steps:

remove the #include <bla> lines from the code
run the GCC preprocessor on the code
add the #include <bla> lines back
run some cleanup routine (optional)

In order to use this script, copy it somewhere (preferably in your PATH directory), and run it using: /path/to/scr.py file.cpp [ARGS] The ARGS are similar to the ones you would give to your g++ command.

For example, let's say we have three files:

FILE: debug.hpp

#pragma once 

#ifdef DEBUG

int recur_depth = 0;

#define dbg(x) {++recur_depth; auto x_=x; --recur_depth; cerr<<string(recur_depth, '\t')<<"\e[91m"<<__func__<<":"<<__LINE__<<"\t"<<#x<<" = "<<x_<<"\e[39m"<<endl;}

template<typename Ostream, typename Cont>
typename std::enable_if<std::is_same<Ostream,std::ostream>::value, Ostream&>::type 
    operator<<(Ostream& os,  const Cont& v){
	os<<"[";
  bool first = true;
	for(auto& x:v){
    if (!first) 
      os << ", ";
    os << x;
    first = false;
  }
	return os<<"]";
}

template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os,  const std::pair<Ts...>& p){
	return os<<"{"<<p.first<<", "<<p.second<<"}";
}

#else
#define dbg(x)
#endif

FILE: dsu.hpp

#pragma once 

using namespace std;

struct DSU {
  vector<int> link;
  
  DSU(int n) : link(n, -1) {}

  int Find(int x) { 
    if (link[x] == -1) return x;
    return link[x] = Find(link[x]);
  }
  
  void Union(int a, int b) {
    a = Find(a); b = Find(b);
    if (a != b) link[a] = b;
  }
};

FILE: sol.cpp

#include <bits/stdc++.h>
#include "debug.hpp"
#include "dsu.hpp"

using namespace std;

int main() {
  int n; cin >> n;
  DSU dsu(n);
  dbg(dsu.link);

  return 0;
}

Output of /path/to/scr.py sol.cpp:

OUTPUT

#include <bits/stdc++.h>

using namespace std;

struct DSU {
  vector<int> link;

  DSU(int n) : link(n, -1) {}

  int Find(int x) {
    if (link[x] == -1) return x;
    return link[x] = Find(link[x]);
  }

  void Union(int a, int b) {
    a = Find(a); b = Find(b);
    if (a != b) link[a] = b;
  }
};

int main() {
  int n; cin >> n;
  DSU dsu(n);

  return 0;
}

Output of /path/to/scr.py sol.cpp -DDEBUG:

OUTPUT

#include <bits/stdc++.h>

int recur_depth = 0;

template<typename Ostream, typename Cont>
typename std::enable_if<std::is_same<Ostream,std::ostream>::value, Ostream&>::type
    operator<<(Ostream& os, const Cont& v){
 os<<"[";
  bool first = true;
 for(auto& x:v){
    if (!first)
      os << ", ";
    os << x;
    first = false;
  }
 return os<<"]";
}

template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os, const std::pair<Ts...>& p){
 return os<<"{"<<p.first<<", "<<p.second<<"}";
}

using namespace std;

struct DSU {
  vector<int> link;

  DSU(int n) : link(n, -1) {}

  int Find(int x) {
    if (link[x] == -1) return x;
    return link[x] = Find(link[x]);
  }

  void Union(int a, int b) {
    a = Find(a); b = Find(b);
    if (a != b) link[a] = b;
  }
};

int main() {
  int n; cin >> n;
  DSU dsu(n);
  {++recur_depth; auto x_=dsu.link; --recur_depth; cerr<<string(recur_depth, '\t')<<"\e[91m"<<__func__<<":"<<9<<"\t"<<"dsu.link"<<" = "<<x_<<"\e[39m"<<endl;};

  return 0;
}

The main idea is that it merges all your #include "bla" files (not the #include <bla> ones, though), and replaces all the #defines and other preprocessor instructions.

Let me know what you think! The tool should work fine in UNIX-based systems (Mac OS X, Linux). I would be happy if someone could test/port this tool for Windows. I think one cool thing about this tool is that it pre-compiles all the #defines, so that most of the output code would look more standardized (C++-ish).

I would personally probably not use this tool too much, as my general approach is to copy-paste implementations and tweak them to the specific problem, but I know a lot of people prefer to use them as black boxes, so this might be useful.

Rev.	By	When	Δ	Comment
en5	bicsi	2020-06-29 17:26:03	16	Script now shouldn't discard comments.
en4	bicsi	2020-06-29 16:59:46	27	Tiny change: 'e code\n- precompile the code\' -> 'e code\n- run the GCC preprocessor on the code\'
en3	bicsi	2020-06-29 16:59:04	2	Tiny change: 'e steps:\n- remove' -> 'e steps:\n\n- remove'
en2	bicsi	2020-06-29 16:58:34	18	Tiny change: 'tebin.com/4icsFNWP (Python 3' -> 'tebin.com/CR0mJXbR (Python 3'
en1	bicsi	2020-06-29 16:52:36	4693	Initial revision (published)

History