Question

In C please :

The tasks in this exam review exercise are structured in levels. You can see the point distribution for the levels at the end. It is strongly recommended that you ensure you have passed all test cases of lower levels before moving up to a higher level. For example, ensure you have completed all Level 0 and 1 tasks before even looking at Level 2 Tasks.

MESSAGE ENCODER

LEVEL 0: (test cases - 50 points)

Start by printing out your name and lab time:

My Name: Dr. Reckinger
My Lab Time: 9:00 AM

Then your code should prompt the user to enter a string of at least 3 characters long:

Enter a string of at least 3 characters (no whitespace):

Make sure strings of up to 200 characters are allowed.

LEVEL 1: (test cases - 25 points)

Ensure the string inputted by the user is at least 3 characters long. If not, repeatedly prompt the user until a valid string has been entered:

Enter a string of at least 3 characters (no whitespace):
Enter a string of at least 3 characters (no whitespace):
Enter a string of at least 3 characters (no whitespace):
.
.
.
Enter a string of at least 3 characters (no whitespace):

Convert the characters in the user's inputted string to a list of integers following the character encoding using the ASCII standard (see Table 2.10.1 for reference, although you do not need any of the details from the table to complete this task). Print the list of integers to the screen (the following is the output if the user had enter "Hello!"):

Your message in ints: 72 101 108 108 111 33 

Next, prompt the user to enter a positive integer representing the integer shift that will be applied to the encoded characters. If the user's string has an odd number of characters, convert the inputted shift to a negative number of the same absolute value.

LEVEL 2: (test cases - 10 points)

Apply the shift to the list of integers and print the shifted list of integers to the screen. For example, the following is the output if the user had entered the 6-character string "Hello!" and a shift of 3:

Your message in ints shifted by 3: 75 104 111 111 114 36 

And, the following is the output if the user had entered the 5-character string "Hello" (no exclamation point) and a shift of 3:

Your message in ints shifted by -3: 69 98 105 105 108 

LEVEL 3: (test cases - 10 points)

Print to screen another string that is the fully encoded message by converting the list of shifted integers back to characters. Here is the full output expected when the user enters the string "Hello!" and a shift of 3:

My Name: Dr. Reckinger
My Lab: 9:00 AM
Enter a string of at least 3 characters (no whitespace):

Your message in ints: 72 101 108 108 111 33 
Enter a positive integer to shift: 

Your message in ints shifted by 3: 75 104 111 111 114 36 
Your encoded message: Khoor$

LEVEL 3+: (test cases - 5 points)

From ASCII Table 2.10.1, notice that only integers between 32 and 126 are valid, so you need to be careful with your shifted integers by wrapping the ASCII table. Thus, an integer of 31 should be assigned to the character '~' (which is #126) and an integer of 128 should be assigned to character '!' (which is #33).

Answer 1

CODE:

#include <stdio.h>
#include<string.h>
int main()
{
    printf("My Name: Dr.Reckinger\nMy Lab Time: 9:00 AM");
    char string[200];
    printf("\nEnter a string of at least 3 characters (no whitespace):");
    scanf("%s",string);
    //printf("%d",strlen(string));
    //Taking input while length less than 3
    while(strlen(string)<3){
        printf("\nEnter a string of at least 3 characters (no whitespace):");
        scanf("%s",string);
    }
    int len=strlen(string),shift;
    int integerArray[len],i=0;
    //Converting to integers
    for(i=0;i<len;i++){
        integerArray[i]=string[i];
    }
    printf("\nYour message in ints:");
    for(i=0;i<len;i++){
        printf("%d ",integerArray[i]);
    }
    printf("\nEnter a positive integer to shift: ");
    scanf("%d",&shift);
    //Changing shift value based on length of the string
    if(len%2==1){
        shift=-shift;
    }
    printf("\nYour message in ints shifted by %d: ",shift);
    for(i=0;i<len;i++){
        integerArray[i]=integerArray[i]+shift;
        printf("%d ",integerArray[i]);
    }
    printf("\nYour encoded message:");
    for(i=0;i<len;i++){
        //Checking whether ASCII value exeeds the max i.e.,, 126
        if(integerArray[i]>126){
            integerArray[i]=integerArray[i]%126;
            integerArray[i]+=31;
        }
        //Checking whether ASCII value decreases the min i.e.,, 32
        if(integerArray[i]<32){
            integerArray[i]=127-(32- integerArray[i]);
        }
        printf("%c",(char)integerArray[i]);
    }
    return 0;
}

//Follow Line number to get correct code

Output: