pex2_7.cpp

数据结构C++代码,经典代码,受益多多,希望大家多多支持

#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

void main(void)
{
	char cryptstr[] = "ngzqtcobmuhelkpdawxfyivrsj";
	
	ifstream  fin;
	ofstream  fout;
	char      infilename[28];
	char      line[80];
	int       i;
	
	cout << "Enter the file name: ";
	cin >> infilename;
	fin.open(infilename, ios::in | ios::nocreate);
	if (!fin)
	{
		cerr << "Cannot open file " << infilename << endl;
		exit(1);
	}
	
	fout.open("crypfile", ios::out | ios::trunc);
	
	// read lines from fin until end of file
	while(fin.getline(line,80,'\n'))
	{
		i = 0;
		// look at each character of the NULL-terminated string
		while (line[i])
		{
			// translate each alphabetic character
			if (isalpha(line[i]))
				// convert to lower case and translate
				line[i] = cryptstr[tolower(line[i]) - 'a'];
			i++;
		}
		fout << line << endl;
	}
}

/*
<Run>

Enter the file name: txt2_7_8.dat

<file "crypfile">

fbmx mx n qnfn cmet fbnf
ftxfx fbt xpeyfmpk fp dwpownllmko
trtwzmxtx 2.7 nkq 2.8.
*/