C++实现文件简单加密与解密（读取文件中的字符，对字符转换，然后写入，完成加密，解密反之）

#include 
#include 
#include 
#include  
const int SIZE = 100; 
using namespace std;

int JiaMi( string infile, string outfile )
{
	cout << "加密文件名: " << infile << "   " << "加密后输出文件名: " << outfile << endl;
	fstream fio( infile.c_str(), ios::in | ios::out );
	
	if( !fio )
	{
		cerr << "文件打开失败" << endl;
		return -1; 
	}
	
	ofstream fout(outfile.c_str());
	if( !fout )
	{
		cerr << "文件打开失败" << endl;
		return -1; 
	}
	
	char chArry[SIZE];
	int readNum = 0;
	
	while( !fio.eof() )
	{
		fio.read( chArry, sizeof(chArry) );
		readNum = fio.gcount();
		for( int i = 0; i < readNum; i++ )
		{
			chArry[i] = ~chArry[i] + 66;  //此处可以更改
		} 
		fout.write( chArry, readNum );
	}
	
	fout.close();
	fio.close();
	cout << "加密完成" << endl; 
	return 0;
}

int JieMi( string infile, string outfile )
{
	cout << "解密文件名: " << infile << "   解密后输出文件名: " << outfile << endl;
	fstream fio( infile.c_str(), ios::in );
	
	if( !fio )
	{
		cerr << "文件打开失败" << endl;
		return -1; 
	}
	
	ofstream fout(outfile.c_str());
	if( !fout )
	{
		cerr << "文件打开失败" << endl;
		return -1; 
	}
	
	char chArry[SIZE];
	int readNum = 0;
	
	while( !fio.eof() )
	{
		fio.read( chArry, sizeof(chArry) );
		readNum = fio.gcount();
		for( int i = 0; i < readNum; i++ )
		{
			chArry[i] = chArry[i] - 66;
			chArry[i] = ~chArry[i];
		}	
		fout.write( chArry, readNum );
	}
	
	fout.close();
	fio.close();
	cout << "解密完成" << endl;
	return 0;
}

int main()
{
	JiaMi( "1.txt", "2.txt" );
	JieMi( "2.txt", "3.txt" );
	system("pause");
	return 0;
}