Thread: Code Breaker

Hi! I have this Code Breaker thing to do and I don't know what's wrong. I'm just a newbie, please help me out.
Here's the instruction:
The program would initially generate 4 distinct random digits number (no 2 digits are the same / unique). Then the user need to guess the random number. The program would give clues by giving 'black' and 'white' markers.
(black marker - exact number in correct digit position
white marker - exact number in wrong position)
The user would also choose the level of difficulty he/she prefers (easy - 10 chances; average - 7 chances; difficult - 5 chances)

So far, here's what I've done (no code regarding difficulty yet 'coz the basic still doesn't work )

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main(void)  {
  int i, stime;
  long ltime;
  int x, j;
  int black = 0;
  int white = 0;
  int code[4];
  int easy[4];
  ltime = time(NULL);
  stime = (unsigned) ltime/2;
  srand(stime);
  code[i] = rand() % (9999-1000+1) + 1000;
  printf("%d", code[i]);
  printf("\n**CODE BREAKER**\n");
  printf("CHANCE #1\n");
  printf("Enter Guess: ");
  scanf("%d", &easy[4]);
  if(code[0] == easy[0]) {
    black = black + 1;
  }
  for(i = 1; i < 4; i++) {
    if(code[0] == easy[i]) {
      white = white + 1;
    }
  }
  if(code[1] == easy[1]) {
    black = black + 1;
  }
  if(code[1] == easy[0]) {
    white = white + 1;
  }
  for(i = 2; i < 4; i++) {
    if(code[1] == easy[i]) {
      white = white + 1;
    }
  }
  if(code[2] == easy[2]) {
    black = black + 1;
  }
  if(code[2] == easy[3]) {
    white = white +1;
  }
  for(i = 0; i < 2; i++) {
    if(code[2] == easy[i]) {
      white = white + 1;
    }
  }
  if(code[3] == easy[3]) {
    black = black + 1;
  }
  for(i = 0; i < 3; i++) {
    if(code[3] == easy[i]) {
      white = white + 1;
    }
  }
  if(black == 4) {
    printf("Congratulations! You guessed the number right!\n");
  } else {
    printf("%d Black Marks\n%d White Marks", black, white);
  }
}

First problem I see is you say you want 4 random numbers but you are only calling rand() once. Second problem is you are assigning to code[i] but you never gave i a value. This is equivalent to saying code[<insert any old integer here>]=...; This makes everything that happens involving code[0], code[1], code[2] etc... undefined.

Third problem: no indentation or code tags so your code is hard to study. Fourth problem: you are not compiling with warnings turned on (if you were you probably would have received a warning about not initializing i).

One of the stranger things going on is dividing the return value of time by 2 before using it as a seed to srand. I can't imagine the rationale for that. And then casting it as unsigned but assigning it to a signed int. Curiouser and curiouser. The standard idiom is:

Code:

    srand((unsigned)time(NULL));

The line with rand is generating a random number between 1000 and 9999, in an attempt to generate all four digits at once. Not only does this procedure allow duplicate digits (contradicating the instructions) but it does not allow the initial digit to be 0. Then, as C99 indicated, it's assigned to lala land. You need to generate and assign the digits separately, testing for duplicates. (Or perhaps a shuffle of the 10 digits and take the first 4.)

However, the first thing to do is to come up with an overall structure for your program. You will need a loop to allow for multiple guesses. And some functions would be nice. Your main might look something like this:

Code:

int main(void) {
    int code[NUM_DIGITS];
    int guess[NUM_DIGITS];
    int num_guesses = 0;
    int max_guesses;
    int correct;

    srand((unsigned)time(NULL));
    max_guesses = chooseLevel();
    generateCode(code);

    do {
        num_guesses++;
        getGuess(guess, num_guesses);
        correct = testGuess(code, guess);
    } while (correct < NUM_DIGITS && num_guesses < max_guesses);

    return 0;
}

The above is not perfect, but it's a start.

And now, some music:

Work so hard I couldn't unwind, get some money saved;
Abuse my love a thousand times, however hard I tried.
Codebreaker, your time has come, can't take your evil way;
Go away, Codebreaker.
Codebreaker!
Codebreaker!
Code!

LED ZEPPELIN - HEARTBREAKER - YouTube