Binary - Case Sensitive Decryption

Binary - Case Sensitive Decryption 

PROBLEM STATEMENT :

The program must accept a string S representing an encrypted message as the input. The program must decrypt the string S and print the message based on the following conditions. 

- The program must split the string S into substrings of equal length 5. 

- For each substring, the program must form a binary representation by replacing the lower case alphabets with 0 and the upper case alphabets with 1. 

Then the program must find the decimal equivalent of each binary representation and replace them with the characters as given below. From 0 to 25 -> a to z. 

26 -> . (dot) 

27 -> , (comma) 

28 -> a SPACE character 

29 -> ? (question mark symbol) 

30 -> ' (single quote) 

31 -> " (double quote) 

Note: The string S contains only alphabets and its length is always a multiple of 5. 

Boundary Condition(s): 

1 <= Length of S <= 1000 

Input Format: 

The first line contains S. 

Output Format: 

The first line contains the decrypted string based on the given conditions. 

Example Input/Output 1: 
Input: () 
abcDEtSAYtmaRKs 
Output: 
dog 

Explanation: 

The given string is abcDEtSAYtmaRKs. 

The 1st substring is abcDE. The binary representation is 00011. 3 -> d. 

The 2nd substring is tSAYt. The binary representation is 01110. 14 -> o. 

The 3rd substring is maRKs. The binary representation is 00110. 6 -> g. 

So the decrypted string is dog, which is printed as the output. 

Example Input/Output 2: 
Input: () 
EytWGeqNKYcbNpqLSXcoAHCUIbgrarZzcpRPvoYGYOQIUQAsHh
Output: 
the "art". 

---

SOLUTION :

C (Programming Language)

      
#include<stdio.h>
#include<stdlib.h>
#include<ctype.h> //For isupper function
#include<string.h> //For strcpy function
#include<math.h> //For pow function
int decimal(char* s)
{
    int sum=0,n=4;
    for(int i=4;i>=0;--i)
    {
        if(isupper(s[i])) sum+=(int)pow(2,(n-i));
    }
    return sum;
}
int main()
{
    char s[10001],ch[]={'.',',',' ','?','\'','"'};
    int l,i,d;
    scanf("%s%n",s,&l); //%n is used to calculate the length
    for(i=0;i<l;i+=5)
    {
        char r[10001];
        strcpy(r,s);
        r[i+l]='\0';
        d=decimal(r+i);
        if(d<=25) printf("%c",'a'+d);
        else printf("%c",ch[d-26]);
    }
}
 

C++ (CPP)

       
#include <bits/stdc++.h>
 
using namespace std;

int main(int argc, char** argv)
{
    int i;
    char ch[]={'.',',',' ','?','\'','"'};
    string s,res="";
    cin>>s;
    for(i=0;i<s.size();++i) 
    {
        if(islower(s[i])) s[i]='0';
        else s[i]='1';
    }
    for(i=0;i<s.size();i+=5)
    {
        int d=stoi(s.substr(i,5),0,2);
        if(d<=25) res+='a'+d;
        else res+=ch[d-26];
    }
    cout<<res;
}
 

JAVA

       
import java.util.*;
public class Hello {

    public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		char[] s=sc.next().toCharArray();
		char[] ch={'.',',',' ','?','\'','"'};
		String res="";
		int i;
		for(i=0;i<s.length;++i) 
		{
		    if(Character.isLowerCase(s[i])) s[i]='0';
		    else s[i]='1';
		}
		for(i=0;i<s.length;i+=5)
		{
		    int d=Integer.parseInt(new String(s).substring(i,i+5),2);
		    if(d<=25) res+=(char)('a'+d);
		    else res+=ch[d-26];
		}
		System.out.println(res);
	}
}
 

PYTHON

       
s=input().strip()
l=len(s)
res=''
lst=[".",","," ","?","'","\""]
for i in range(0,l,5):
    r=list(s[i:i+5])
    for j in range(5):
        if r[j].islower():
            r[j]='0'
        else:
            r[j]='1'
    d=int(''.join(r),2)
    if d<=25:
        res+=chr(97+d)
    else:
        res+=lst[d-26]
print(res)
 

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