Utility.h

#ifndef _UTILITY_H_
#define _UTILITY_H_

#include <ctime>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <queue>
#include <set>

#define _BITSET_ //use bit set to represent the adjacency matrix
#define _STATISTIC_
#define _KERNEL_
#define _RECOLOR_
//#define _BRACH_ON_COLOR_

//#define NDEBUG
#include <cassert>

#ifdef _BITSET_
#define set_bit(array, pos) (((array)[(pos)>>3]) |= (1<<((pos)&7)))
#define reverse_bit(array, pos) (((array)[(pos)>>3]) ^= (1<<((pos)&7)))
#define test_bit1(array, pos) (((array)[(pos)>>3])&(1<<((pos)&7)))
#define test_bit(array, pos) ((((array)[(pos)>>3])>>((pos)&7))&1)
#else
#define set_bit(array, pos) (((array)[pos]) = 1)
#define reverse_bit(array, pos) (((array)[pos]) = 1- ((array)[pos]))
#define test_bit(array, pos) ((array)[pos])
#endif

//#define ui unsigned int
//#define ept unsigned long
using ui = int; // vertex type
using ept = unsigned long; // edge pointer type; unsigned int can be used to process upto two billion undirected edges

#define pb push_back
#define mp make_pair

class Utility {
public:
	static FILE *open_file(const char *file_name, const char *mode) {
		FILE *f = fopen(file_name, mode);
		if(f == nullptr) {
			printf("Can not open file: %s\n", file_name);
			exit(1);
		}

		return f;
	}

	static std::string integer_to_string(long long number) {
		std::vector<ui> sequence;
		if(number == 0) sequence.pb(0);
		while(number > 0) {
			sequence.pb(number%1000);
			number /= 1000;
		}

		char buf[5];
		std::string res;
		for(ui i = sequence.size();i > 0;i --) {
			if(i == sequence.size()) sprintf(buf, "%u", sequence[i-1]);
			else sprintf(buf, ",%03u", sequence[i-1]);
			res += std::string(buf);
		}
		return res;
	}
};

#endif