Having trouble outputting from a file

[CodeNovice01]

I'm using a playfair program, and i'm having trouble with outputting to my file. Everything outputs correctly, minus the encryption of my text file.

the "message.in" is just a generic text file with a random sentence nothing specific.

#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;

ifstream inf("message.in");
ofstream out("reply.out");

struct node
{
	int i, j;
};

struct node search(char a[5][5],char p)
{
	struct node l;
	for(int u=0;u<5;u++)
	{
		for(int v=0;v<5;v++)
		{
			if(a[u][v] == p)
			{
				l.i = u;
				l.j = v;
				return l;
			}
		}
	}
}

string encryption(string pt,string key)
{
	//Creates the 5x5 required matrix
	char a[5][5];
	bool visited[26]={0};

	int p=0,q=0;

	//Creates the key input
	for(int i=0;i<key.length();i++)
	{
		if(visited[key[i]-65]==0)
		{
			a[p][q] = key[i];
			visited[key[i]-65] = 1;
			if(q+1 < 5)
				q++;
			else{
				p++;
				q=0;
			}
		}
	}

	for(char t='A';t<='Z';t++)
	{
		if(t!='J')
		{
			if(visited[t-65]==0)
			{
				a[p][q] = t;
				visited[t-65] = 1;
				if(q+1 < 5)
					q++;
				else
				{
					q=0;
					p++;
				}
			}
		}
	}

	for(int i=0;i<5;i++)
	{
		for(int j=0;j<5;j++)
			out<<a[i][j]<<" ";
		out<<endl;
	}

	//Encrypts Plaintext
	string ct = "";
	for(int r=0;r<pt.length();r=r+2)
	{
		struct node x = search(a,pt[r]);
		struct node y = search(a,pt[r+1]);
		// if same row
		if (x.i == y.i)
		{
			ct = ct + a[x.i][((x.j)+1)%5];
			ct = ct + a[y.i][((y.j)+1)%5];
		}
		// if same col
		else if (x.j == y.j)
		{
			ct = ct + a[((x.i)+1)%5][x.j];
			ct = ct + a[((y.i)+1)%5][y.j];
		}
		// diagonal
		else
		{
			ct = ct + a[x.i][y.j];
			ct = ct + a[y.i][x.j];
		}
	}
	return ct;
}

string keypreprocess(string k)
{
	string key = "";
	for(int i=0;i<k.length();i++)
	{
		if(k[i]!=' ')
		{
			if(toupper(k[i])=='J')
				key += 'I';
			else
				key += toupper(k[i]);
		}
	}
	return key;
}

string ptpreprocess(string p)
{
	string pt = "", pp = "";

	for(int i=0;i<p.length();i++)
	{
		if(toupper(p[i])=='J')
			pp += 'I';
		else if(p[i]!=' ')
			pp += p[i];
	}
	for(int i=0;i<pp.length();i+=2)
	{
		if(pp[i]==pp[i+1]){
			pt += toupper(pp[i]);
			pt += 'X';
			i--;
		}
		else
		{
			if(i==pp.length()-1)
			{
				pt += toupper(pp[i]);
				pt += 'X';
			}
			else
			{
				pt += toupper(pp[i]);
				pt += toupper(pp[i+1]);
			}
		}
	}
	return pt;
}

int main()
{
	string pt,key = "Tennessee";
	out<<"Plain Text: ";
	getline(inf,pt);
	pt = ptpreprocess(pt);
	key = keypreprocess(key);
	out<<pt<<" \nKey: "<<key<<endl;
	out<<encryption(pt,key);
}

[jlb]

I would say that the first thing you need to do is pay attention to your compiler warnings, you should be getting several. Never ignore warnings, they are a good sign of problems with your code.

 In function 'std::string encryption(std::string, std::string)':
40:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
83:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 In function 'std::string keypreprocess(std::string)':
112:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 In function 'std::string ptpreprocess(std::string)':
129:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
136:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
145:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 In function 'node search(char (*)[5], char)':
29:1: warning: control reaches end of non-void function [-Wreturn-type]

[seeplus]

In function search(), if p isn't found there's nothing returned - but the function requires a type node returned. Note there's no need to use struct node for the return type. Just node is OK with C++. This is the main issue reported by the warnings (L29)