main.cpp

迷宫问题

#include <iostream>
#include <string>
#include "building.h"
using namespace std;

extern Building *get_Stack();
extern Building *get_Queue();
extern Building *get_Opt();

void printErrMes();			//print out error message if the command line arguments are not legal
void printHelp();			//print out help message

int main(int argc, char *argv[])
{
	Building* theBuilding;
	string infilename="building.txt", outfilename="escape.txt";
	bool legal = 0;
	for (int i=0; i<argc; i++)					//Read command line, check if the infile and outfile are specified
	{
		if (!strcmp(argv[i], "-H"))
			printHelp();
		if (!strcmp(argv[i], "-I"))
		{
			infilename=argv[++i];
			for (int j=i+1; j<argc; j++)
			{
				if( !strcmp(argv[j],"-H")||!strcmp(argv[j],"-I")||!strcmp(argv[j],"-O")
					||!strcmp(argv[j],"Stack")||!strcmp(argv[j],"Queue")||!strcmp(argv[j],"Opt"))
					break;
				else
					infilename+=" "; 
				infilename+=argv[j];
			}
		}
		if (!strcmp(argv[i], "O"))
		{
			outfilename=argv[++i];
			for (int j=i+1; j<argc; j++)
			{
				if( !strcmp(argv[j],"-H")||!strcmp(argv[j],"-I")||!strcmp(argv[j],"-O")
					||!strcmp(argv[j],"Stack")||!strcmp(argv[j],"Queue")||!strcmp(argv[j],"Opt"))
					break;
				else
					outfilename+=" ";
				outfilename+=argv[j];
			}
		}
	}

	//Read the command line, choose the strategy: stack, queue or opt?
	//Use the parameter of file name(if there is one), construct a specified derived class 
	//to the base class Building, pointing "theBuilding" to it
	for (int i=0; i<argc; i++)										
	{
		char str_stack[6], str_queue[6], str_opt[4];
		strcpy(str_stack, "Stack");strcpy(str_queue, "Queue");strcpy(str_opt, "Opt");
	
		if (!strcmp(argv[i], str_stack))               //strcmp 当argv[i]与str_stack 相等时返回0
		{
			if(legal)				
				printErrMes();				//若legal==1, 已经找到指定的三种策略之一，重复指定为非法
			theBuilding =get_Stack();
			if (infilename!="building.txt")			
				*theBuilding = Stack_Building(infilename);
			legal=1;
		}
		if (!strcmp(argv[i], str_queue))
		{
			if(legal)				
				printErrMes();
			theBuilding=get_Queue();
			if (infilename!="building.txt")			
				*theBuilding =Queue_Building(infilename);
			legal = 1;
		}
		if (!strcmp(argv[i], str_opt))
		{
			if(legal)				
				printErrMes();
			theBuilding=get_Queue();
			if (infilename!="building.txt")			
				*theBuilding = Queue_Building(infilename);			//用queue的算法作为最优算法
			legal = 1;
		}
	}
	if(!legal)
		printErrMes();
	
	if (!theBuilding->escape())
		theBuilding->printMap(outfilename);
	else
	{
		cout<<endl<<"Escaping route is:\n\n";
		theBuilding->printMap(outfilename);
	}
		
	return 0;
}



void printErrMes()
{
	cout<<"Illegal command line arguments!\n";
	exit (1);
}
void printHelp()
{
	cout<<"INTRODUCTION:\n"
		<<"This program finds the way to escape from a building\n"
		<<"Start point is \"S\", exit points are \"H\" and \"P\", the route is in the output file, marking each step with the direction.\n"
		<<"If there is no way out, a message of failure will be printed.\n"
		<<"For more detailed introduction, refer to the project description file.\n\n";

	cout	<<"Command \"Stack\" will use the stack-based routing scheme"<<endl
			<<"Command \"Queue will use the queue-based routing scheme"<<endl
			<<"Command \"Opt\" will use the optimal routing scheme"<<endl
			<<"The input filename is after the \"I\" flag, if it does not appear, the file \"building.txt\" will be used."<<endl
			<<"The output filename is after the \"O\" flag, if it does not appear, the file \"escape.txt\" will be used."<<endl;
}