write the //TODO part of the program:

write the //TODO part of the program:

/***************************************************************************
* scramble.c
*
* Problem Set 3
*
* Implements Scramble with CS50.
*
* Usage: scramble [#]
*
* where # is an optional grid number.
***************************************************************************/

#include [removed]
#include [removed]
#include [removed]
#include [removed]
#include [removed]
#include [removed]
// duration of a game in seconds
#define DURATION 30
// grid’s dimensions
#define DIMENSION 4
// maximum number of words in any dictionary
#define WORDS 172806
// maximum number of letters in any word
#define LETTERS 29
// default dictionary
// http://www.becomeawordgameexpert.com/wordlists.htm
#define DICTIONARY “words”
// for logging
FILE* log;
// grid
char grid[DIMENSION][DIMENSION];
// flags with which we can mark grid’s letters while searching for words
bool marks[DIMENSION][DIMENSION];
// defines a word as having an array of letters plus a flag
// indicating whether word has been found on grid
typedef struct
{
bool found;
char letters[LETTERS + 1];
}
word;
// defines a dictionary as having a size and an array of words
struct
{
int size;
word words[WORDS];
}
dictionary;
// prototypes
void clear(void);
bool crawl(string letters, int x, int y);
void draw(void);
bool find(string s);
void initialize(void);
bool load(string s);
bool lookup(string s);
void scramble(void);
// This is Scramble.
int main(int argc, string argv[])
{
// ensure proper usage
if (argc > 2)
{
printf(“Usage: %s [#]\n”, basename(argv[0]));
return 1;
}
// seed pseudorandom number generator
if (argc == 2)
{
int seed = atoi(argv[1]);
if (seed <= 0) { printf("Invalid grid.\n"); return 1; } srand(seed); } else srand(time(NULL)); // determine path to dictionary string directory = dirname(argv[0]); char path[strlen(directory) + 1 + strlen(DICTIONARY) + 1]; sprintf(path, "%s/%s", directory, DICTIONARY); // load dictionary if (!load(path)) { printf("Could not open dictionary.\n"); return 1; } // initialize the grid initialize(); // initialize user's score int score = 0; // calculate time of game's end int end = time(NULL) + DURATION; // open log log = fopen("log.txt", "w"); if (log == NULL) { printf("Could not open log.\n"); return 1; } // accept words until timer expires while (true) { // clear the screen clear(); // draw the current state of the grid draw(); // log board for (int row = 0; row < DIMENSION; row++) { for (int col = 0; col [removed]= end) { printf("\033[31m"); // red printf("Time: %d\n\n", 0); printf("\033[39m"); // default break; } // report time remaining printf("Time: %d\n\n", end - now); // prompt for word printf("> “);
string s = GetString();
// quit playing if user hits ctrl-d
if (s == NULL)
break;
// log word
fprintf(log, “%s\n”, s);
// check whether to scramble grid
if (strcmp(s, “SCRAMBLE”) == 0)
scramble();
// or to look for word on grid and in dictionary
else
{
if (find(s) && lookup(s))
score += strlen(s);
}
}
// close log
fclose(log);
return 0;
}
/**
* Clears screen.
*/
void clear()
{
printf(“\033[2J”);
printf(“\033[%d;%dH”, 0, 0);
}
/**
* Crawls grid recursively for letters starting at grid[x][y].
* Returns true iff all letters are found.
*/
bool crawl(string letters, int x, int y)
{
// if out of letters, then we must’ve found them all!
if (strlen(letters) == 0)
return true;
// don’t fall off the grid!
if (x [removed]= DIMENSION)
return false;
if (y [removed]= DIMENSION)
return false;
// been here before!
if (marks[x][y])
return false;
// check grid[x][y] for current letter
if (grid[x][y] != letters[0])
return false;
// mark location
marks[x][y] = true;
// look left and right for next letter
for (int i = -1; i <= 1; i++) { // look down and up for next letter for (int j = -1; j <= 1; j++) { // check grid[x + i][y + j] for next letter if (crawl(&letters[1], x + i, y + j)) return true; } } // unmark location marks[x][y] = false; // fail return false; } /** * Prints the grid in its current state. */ void draw(void) { // TODO } /** * Returns true iff word, s, is found in grid. */ bool find(string s) { // word must be at least 2 characters in length if (strlen(s) < 2) return false; // search grid for word for (int row = 0; row < DIMENSION; row++) { for (int col = 0; col < DIMENSION; col++) { // reset marks for (int i = 0; i < DIMENSION; i++) for (int j = 0; j < DIMENSION; j++) marks[i][j] = false; // search for word starting at grid[i][j] if (crawl(s, row, col)) return true; } } return false; } /** * Initializes grid with letters. */ void initialize(void) { // http://en.wikipedia.org/wiki/Letter_frequency float frequencies[] = { 8.167, // a 1.492, // b 2.782, // c 4.253, // d 12.702, // e 2.228, // f 2.015, // g 6.094, // h 6.966, // i 0.153, // j 0.747, // k 4.025, // l 2.406, // m 6.749, // n 7.507, // o 1.929, // p 0.095, // q 5.987, // r 6.327, // s 9.056, // t 2.758, // u 1.037, // v 2.365, // w 0.150, // x 1.974, // y 0.074 // z }; int n = sizeof(frequencies) / sizeof(float); // iterate over grid for (int row = 0; row < DIMENSION; row++) { for (int col = 0; col < DIMENSION; col++) { // generate pseudorandom double in [0, 1] double d = rand() / (double) RAND_MAX; // map d onto range of frequencies for (int k = 0; k < n; k++) { d -= frequencies[k] / 100; if (d < 0.0 || k == n - 1) { grid[row][col] = 'A' + k; break; } } } } } /** * Loads words from dictionary with given filename, s, into a global array. */ bool load(string s) { // open dictionary FILE* file = fopen(s, "r"); if (file == NULL) return false; // initialize dictionary's size dictionary.size = 0; // load words from dictionary char buffer[LETTERS + 2]; while (fgets(buffer, LETTERS + 2, file)) { // overwrite \n with \0 buffer[strlen(buffer) - 1] = '\0'; // capitalize word for (int i = 0, n = strlen(buffer); i < n; i++) buffer[i] = toupper(buffer[i]); // ignore SCRAMBLE if (strcmp(buffer, "SCRAMBLE") == 0) continue; // copy word into dictionary dictionary.words[dictionary.size].found = false; strncpy(dictionary.words[dictionary.size].letters, buffer, LETTERS + 1); dictionary.size++; } // success! return true; } /** * Looks up word, s, in dictionary. Iff found (for the first time), flags word * as found (so that user can't score with it again) and returns true. */ bool lookup(string s) { // TODO return false; } /** * Scrambles the grid by rotating it 90 degrees clockwise, whereby * grid[0][0] rotates to grid[0][DIMENSION - 1]. */ void scramble(void) { // TODO }