Please code these two functions in C:

#include #include

#define MAX_STR_LEN 2048

void caesar_cipher(unsigned char plaintext[MAX_STR_LEN], int displacement) { // This function encodes the input text in plaintext[] using the caesar // cipher process with the specified displacement. // // The function must ensure that the 'end-of-string' delimiter is preserved, // and that no other character can become the 'end-of-string'. // // You want to make sure you understand what values can be stored in each // entry of the plaintext[] string, and you'll want to look at an ASCII table // to check that your function does the right thing. // // *** TEST your code with multiple input strings, and verify it works in // every case! if you get incomplete because your function failed our // tests it means you did not test carefully enough. // TO DO: Implement this function }

void caesar_decipher(unsigned char cryptotext[MAX_STR_LEN],int displacement) { // This function reverses the encryption process and returns the original // text given the encrypted string and the displacement used to encode it. // // The function has the same constraints as 'caesar_cipher()', that is, it // must respect the 'end-of-string' delimiter, and ensure no other // character becomes 'end-of-string' after decoding. // // Be smart about how you implement this function! // TO DO: Implement this function }

#ifndef __testing

int main() { unsigned char a_passage[5][MAX_STR_LEN]={"When did the world begin and how? I asked a lamb, a goat, a cow: ", "Whats it all about and why? I asked a hog as he went by: ", "Where will the whole thing end, and when? I asked a duck, a goose and a hen: ", "And I copied all the answers too, A quack, a honk, an oink, a moo. ", " --- Robert Clairmont "}; printf("**** Original input text lines: "); for (int i=0; i<5; i++) printf("%s",a_passage[i]);

// Encode the input test lines caesar_cipher(&a_passage[0][0],15); caesar_cipher(&a_passage[1][0],122); caesar_cipher(&a_passage[2][0],-175); caesar_cipher(&a_passage[3][0],22); caesar_cipher(&a_passage[4][0],-17);

printf(" **** Encrypted text lines: "); for (int i=0; i<5; i++) printf("%s",a_passage[i]);

// Decode the encrypted strings caesar_decipher(&a_passage[0][0],15); caesar_decipher(&a_passage[1][0],122); caesar_decipher(&a_passage[2][0],-175); caesar_decipher(&a_passage[3][0],22); caesar_decipher(&a_passage[4][0],-17);

printf(" **** Decoded text lines (should be identical to original input!): "); for (int i=0; i<5; i++) printf("%s",a_passage[i]); return 0; }

#endif