Question

ior new tr k%2005%281 %29, You are just hired by Google as a senior software developer and your supervisor assigns you the following task: You are responsible for the development of a program that encrypts and decrypts text messages using the Caesar shift, which is one of the oldest and widely known forms of encryption Caesar shift is a type of substitution encryption method in which each letter in the text is 'shifted' a fixed mumber of positions down the alphabet. For example, a shift of 3 would change the letter 'A' to D, B' to E', and so on. Z would shift back around to C". The method is named after Julius Caesar, who used it to communicate with his generals Your program should prompt the user to enter a message, it will then encode the message by shifting it4 characters over, and decode it again. A sample run of your program should look like this: Enter a message: this is a test! THIS IS A TEST! THIS IS A TEST! Requirements: The program will prompt the user to enter a message . You must declare two functions, one to encode and the other to decode the message .You can store the message m an array of characters, C-String, os string You are free to choose any of the three . The message must be converted to upper case o You are only expected to encode and decode letters, not numbers or symbols. . Name the source file for your program program5.cpp

Answer 1

#include<stdio.h>
#include<string.h>
#include <ctype.h>
#include <iostream>
#include<string>
using namespace std;
void encode(string& arr,int n);
void decode(string& arr,int n);

int main()
{
string arr;int shift=4,i;
printf("Enter a message : ");
std::getline (std::cin,arr);//accept string
for(i=0;i<arr.size();i++)//convert to uppercase
{
arr[i]=toupper(arr[i]);
}
cout<<arr<<endl;//print uppercase
encode(arr,arr.size());//encode message
cout<<arr<<endl;
decode(arr,arr.size());//decode message
cout<<arr<<endl;
return 0;
}
void encode(string& arr,int n)
{int i=0;
for(i=0;i<n;i++)
if(isalpha(arr[i]))//if alphabet then shift 4
{arr[i]=(arr[i]-'A'+4)%26+'A';}
}
void decode(string& arr,int n)
{int i=0;
for(i=0;i<n;i++)
if(isalpha(arr[i]))//if alphabet then shift -4
{arr[i]=(arr[i]-'A'-4)%26+'A';}
}

四ウ勇 緊自49 all 10:37 AM hitesh 1-0N> status x someone com X @lor New Tr K%2 @replit-Thosec x c++-why is st X "% Passing by refe Χ C++-How toc H online C++ Co X x Secure https://repl.it/repls/ThoseCourt @anonymous/ThosecourteousEnvironments C No description Sign up Files O saved gcc version 4.6.3 share main.cpp Enter a message this is a test! THIS IS A TEST! main.cpp include<stdio.h» #include<string.h> 1 THIS IS A TEST! 3 #include <ctype.h> #include <iostream» 5 #includec string> 6 using namespace std; 7 void encode(string& arr,int n); 8 void decode(string& arr,int n); 1e 11 int main() 13 string arr; int shift-4,1; 14 printf("Enter a message; 15 std: :getline (std::cin,arr);//accept string 16 for(i-e;iarr. size();า++)//convert to uppercase 17 ▼ 18 arr[i]-toupper(arr[i]); 19 2e cout<<arr<cendl;//print uppercase 21 encode(arr,arr.size));//encode message 22 cout<<arr<<endl 23 decode(arr,arr.size));//decode message 24 cout<<arr<cendl; 25 return ; 26 27 void encode(string& arr,int n) 28 int i-0; 29 for(1-0;1<n;1++) 3e if(isalpha(arr[i]))//if alphabet then shift 4 31 {arr[i]-(arr[i]-'A'+4)%26+'A';}