this should be done in C Our method will involve analyzing a string and picking the 5 most common letters in that string. We will then compute how far each of these is from the letter ‘e’.We will then produce 5 possible decryptions of the string by:Decryption 1 will be from comparing how far the most popular letter is from the letter “e”Decryption 2 will be from comparing how far the second most popular letter is from the letter “e” Decryption 3 will be from comparing how far the third most popular letter is from the letter “e”Decryption 4 will be from comparing how far the fourth most popular letter is from the letter “e”Decryption 5 will be from comparing how far the fifth most popular letter is from the letter “e”

Define find_common_letters() function to find the five most common letters in a string. Define decrypt() function to produce five possible decryptions of a string. In the main() function, prompt the user for a string to decrypt. Allocate memory for the five decryptions. Create an array of 26 elements to store the frequency of each letter in the string. Iterate through the string to count the frequency of each letter. Sort the array of frequencies to find the five most common letters. Use the indices of the five most common letters to compute their distances from the letter 'e'. Iterate through the original string and apply the shifts computed earlier to each letter to produce the five possible decryptions. Print the results to the console. Free the memory allocated for the decryptions.#include <stdio.h>#include <string.h>#include <stdlib.h> #define ALPHABET_SIZE 26#define NUM_DECRYPTIONS 5 // Function to find the five most common letters in a stringvoid find_common_letters(const char *str, char *common, int *freq){ // Initialize frequency array to 0 memset(freq, 0, sizeof(freq[0]) * ALPHABET_SIZE); // Count the frequency of each letter in the string int len = strlen(str); for (int i = 0; i < len; i++) { char c = str[i]; // Ignore non-alphabetic characters if (c >= 'A' && c <= 'Z') { freq[c - 'A']++; } } // Sort the frequency array to find the five most common letters for (int i = 0; i < ALPHABET_SIZE - 1; i++) { for (int j = i + 1; j < ALPHABET_SIZE; j++) { if (freq[i] < freq[j]) { // Swap letters char tmp = common[i]; common[i] = common[j]; common[j] = tmp; // Swap frequencies int t = freq[i]; freq[i] = freq[j]; freq[j] = t; } } } // Keep only the five most common letters common[5] = '\0';} // Function to produce five possible decryptions of a stringvoid decrypt(const char *str, char *decryptions[NUM_DECRYPTIONS]){ // Create arrays to store the common letters and their frequencies char common[ALPHABET_SIZE + 1]; int freq[ALPHABET_SIZE]; // Initialize common letters array for (int i = 0; i < ALPHABET_SIZE; i++) { common[i] = 'A' + i; } // Find the five most common letters in the string find_common_letters(str, common, freq); // Compute the shift distance for each decryption int shift[NUM_DECRYPTIONS]; for (int i = 0; i < NUM_DECRYPTIONS; i++) { // Compute the distance from the letter 'e' (index 4) shift[i] = (common[i] - 'A') - 4; // Shift the letters in the string to produce the decryption int len = strlen(str); for (int j = 0; j < len; j++) { char c = str[j]; // Ignore non-alphabetic characters if (c >= 'A' && c <= 'Z') { // Shift the letter by the computed distance int index = (c - 'A' + shift[i]) % ALPHABET_SIZE; if (index < 0) { index += ALPHABET_SIZE; } decryptions[i][j] = 'A' + index; } else { // Copy non-alphabetic characters as-is decryptions[i][j] = c; } } }}int main(void){ // Prompt the user for a string to decrypt char str[256]; printf("Enter a string to decrypt: "); scanf("%255s", str); // Allocate memory for the decryptions char *decryptions[NUM_DECRYPTIONS]; for (int i = 0; i < NUM_DECRYPTIONS; i++) { decryptions[i] = malloc(strlen(str) + 1); } // Produce the five possible decryptions decrypt(str, decryptions); // Print the results for (int i = 0; i < NUM_DECRYPTIONS; i++) { printf("Decryption %d: %s\n", i + 1, decryptions[i]); } // Free the memory allocated for the decryptions for (int i = 0; i < NUM_DECRYPTIONS; i++) { free(decryptions[i]); } return 0;}