Cryptography-Code-Bunch/PolybiusSquareCipher.cpp at master · astrodestroyergithub/Cryptography-Code-Bunch · GitHub

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

char table[5][5];

string encrypt(string pt)
{
    string encpt="";
    int l = pt.length();
    char encpt1[l+1];
    strcpy(encpt1,pt.c_str());
    for(int i=0;i<l;i++)
        for(int j=0;j<5;j++)
            for(int k=0;k<5;k++)
            {
                if(encpt1[i]==table[j][k])
                {
                    char ch = j+48+1;
                    string row(1,ch);
                    encpt=encpt+row;
                    ch = k+48+1;
                    string col(1,ch);
                    encpt=encpt+col;
        }
    }
    return encpt;
}

string decrypt(string encpt)
{
    string decpt="";
    int l = encpt.length();
    char decpt1[l+1];
    strcpy(decpt1,encpt.c_str());
    for(int i=0;i<l;i=i+2)
    {
        int row, col;
        row=decpt1[i];
        row-=48;
        col=decpt1[i+1];
        col-=48;
        string s(1,table[row-1][col-1]);
        decpt=decpt+s;
    }
    return decpt;
}

int main()
{
    int num = 65, i=0;
    while(num<=90)
    {
        if(num!=74)
        {
            int j = i/5;
            char ch = num;
            table[j][i%5] = ch;
            i++;
        }
        num++;
    }
    string pt,encpt,decpt;

    cout<<"Enter plaintext: ";
    cin>>pt;
    encpt = encrypt(pt);
    cout<<"Encrypted text: "<<encpt;
    decpt = decrypt(encpt);
    cout<<"\nDecrypted text: "<<decpt;
    return 0;
}