a message has been encrypted and put in the file \"secret.txt\". The original me

Question

a message has been encrypted and put in the file "secret.txt". The original message was inputted word by word. to encrypt the n th word in a file, each small letter in the word was "rotated up" by n plus the length of the word, with "wraparound".

write a c++ code program which decrypts the secret message and output the plain text result. you should input the encrypted message ("secret.txt")word by word, undo the encryption, output result. .
ex: tli xbpjr jzwev mve ufxapo yfob dro xmlk qbt. A qxgs wb jxu zsfv cwpdano fg ikoo, wpo u spmmjoh stone gq yqtvj uxp jo wkh hayn.

should be : the quick brown fox jumped over the lazy dog. A bird in the hand gathers no moss, but a rolling Stone is worth two in the bush.

In the illustration above, the first encrypted word is tli. The t need no decryption. The l should be rotated down by 1+3=4 ( we are in the first word. and the word length is 3.

Explanation / Answer

#include <cstdlib>
#include <iostream>
#include <string>
#include <fstream>

using namespace std;

int main(){
string buff;
string words[100];
ifstream myfile("secret.txt");
int i = 0;
int word_count = 0, new_sentence = 1;
if(!myfile)
{
    cout<<"Error opening output file"<<endl;
    system("pause");
    return -1;
}
while(!myfile.eof())
{
    getline(myfile,buff,' ');
    cout<<buff<<" ";
    words[i] = buff;
     //cout<<"2."<<a<<" "<<words[a]<<" ";
    i++;
}
cout<<endl;
word_count = i--;
  
   for(i = 0; i<word_count;i++){
       buff = words[i];
       int l = buff.size();
       int rotateBy, offset = 0;
      
       char ch;
       for(std::string::iterator it = buff.begin(); it != buff.end(); ++it) {
           rotateBy = (i%26)+l+1;
             if (*it != ',' && *it != '.' && new_sentence == 0){
               
               offset =    ((*it)-rotateBy);
           //   cout << offset;
               if (offset < 97)
                   offset += 26;
               else if (offset > 122)
                   offset -= 26;
                 ch = offset;
               *it = ch;
               //new_sentence = 0;
           }
           else if (*it == '.')
               new_sentence = 1;
           else
               new_sentence = 0;
       }
       cout<<buff<<" ";
   }
  
}

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.