Question

Assignment in C:

prompt the user to enter secret message that is terminated by presding Enter. You can assume that the the length of this message will be less than 100 characters. You will then parae this message, character by character, converting them to lower case, and find corresponding characters in the words found in the key text word array. Once a character match is found, you will write the index of the word and the index of the character to a character string that you will later write out to the text file. Spaces are to be placed into the text as found in the message and will be used to delimit the separate words in the secret message. Once the message has been encoded, prompt the user for the name of a file to save the encoded message to, and save it to that file

Answer 1

Program Code Screenshot



Program Sample Console Input/Output Screenshot

out.txt after execution

Program Code to Copy

#include <stdlib.h>
#include <stdio.h>



int main(int argc, char *argv[])
{
    // create a key text work array for encryption
    // we can add more characters in this for encoding
    const int length=6;
    char key_text[6][10]={"qwe", "rtyui", "opasd", "fghjkl", "zxcv", "bnm"};

    // prompt the user to enter secret message that is terminated by presding Enter.
    printf("Enter Secret Message: ");

    // can assume that the the length of this message will be less than 100 characters
    char buffer[100];

    //take input
    scanf("%[^\t\n]s",buffer); 

    // declare variable to store encrypted message and its counter
    char message[200];
    int k=0;

    // parse the message character by character
    int pos=0;
    while(buffer[pos]!='\0'){
        char x = buffer[pos];

        // check for space
        // Spaces are to be placed into the text as found in the message and will be used to delimit the separate words in the secret message
        if(x==' '){
            message[k++]=' ';
            pos++;
            continue;
        }

        int found=0;//variable to check if character if found

        int i=0, j=0; //indexes to be traversed

        // search this character in key text array
        for(i=0;i<length;i++){
            j=0;
            while(key_text[i][j]!='\0' && key_text[i][j]!=x){
                j++;
            }
            if(key_text[i][j]==x){
                found=1;
                break;
            }
        }
        if(found==1){
            // add index of word and character in the message
            char str[100];
            itoa(i, str, 100);
            int cp =0;
            while(str[cp!='\0']){
                message[k++]=str[cp++];
            }
            itoa(j, str, 100);
            cp =0;
            while(str[cp!='\0']){
                message[k++]=str[cp++];
            }
        }else{
            printf("character %c not found in key_text array\n", x);
        }
        pos++;
    }
    message[k]='\0';

    // Once the message has been encoded, prompt the user for the name of a file 
    char fileName[100];
    printf("Enter file to save encoded message: ");
    scanf("%s", fileName);

    //save encoded message to this file
    FILE *fp;
    fp = fopen(fileName, "w+");
    fprintf(fp, "%s", message);
    fclose(fp);
}