Help with writing functions using arrays

[chrisjg04]

I need some help with passing arrays through a function. A portion of the program calls for us to determine the number of digits incorrectly guessed.

// Pre-conditions: board and answer are of length NUM_PEGS and store the player's
//                 guess and the correct board, respectively.
// Post-conditions: returns the number of pegs that match at INCORRECT spots
//                  after "erasing" those pegs that match at correct spots.
int numWrongPlaceMatches(int board[], int answer[]) {
   
       
    // Create temporary copies of both boards, since we'll need to make changes
    // to each during this process and we don't want to ruin the original
    // state of either board.
    int i, temp1[5], temp2[5];
    for(i=0; i<NUM_PEGS; i++){
             temp1[i] = board[i];
             temp2[i] = answer[i];
             }
    
   
    
    // Mark out the spots on the board and answer that match up perfectly.
    for(i=0; i<NUM_PEGS; i++){
             markOutCorrect;
             }
    
    // Go through the board and try to match each peg on the board to
    // a spot on the answer. Hint: A double loop is needed.
    // Note: Remember to "mark" an answer when a match is found.
    int match, wrong=0;
    for(i=0; i<NUM_PEGS; i++){
     if (answer[i] != MARKED_ANSWER)
        wrong++;
        }
    for(i=0; i<NUM_PEGS; i++){
             board[i] = temp1[i];
             answer[i] = temp2[i];
    }
     
     return wrong;
}                  

// Pre-conditions: dest and source are both have the given length.
// Post-conditions: All values from source are copied into the corresponding
//                  locations in dest.
void copyArray(int dest[], int source[], int length) {
     int i;
     for(i=0; i<NUM_PEGS; i++){
              dest[i] = source[i];
     }
    
}

// Pre-conditions: board and answer are of length NUM_PEGS.
// Post-conditions: For each corresponding slot that matches in both boards,
//                  the slots are changed to equal each board's appropriate
//                  marker.
void markOutCorrect(int board[], int answer[]) {
     int i;
     for(i=0; i<NUM_PEGS; i++){
              if(board[i] == answer [i]){
                          board [i] = MARKED_BOARD;
                          answer[i] = MARKED_ANSWER;
              }
     }
              
}

That is the code that I have so far for that section. I am not looking for anyone to answer this for me, I only wish to understand how I would go about solving this. If anyone could help it would be greatly appreciated.

[Salem]

void foo ( int a );
int main ( ) {
  int fred;
  foo( fred );
}

vs

void foo ( int a[] );
int main ( ) {
  int fred[100];
  foo( fred );
}

[sunny1778]

You can use pointers. It is the fastest and the best solution.

[quzah]

You can use pointers. It is the fastest and the best solution.

Since you weren't clear as to what you were referencing with this statement, let me point out that this:

void foo( char bar[] )

Is the same as:

void foo( char *bar )

Quzah.

[chrisjg04]

Ok I got it able to calculate numiperfectmatches now, but for some reason the do-while look that this function is in in main isn't executing. Is there something that I need to add to the function for this loop to execute?

Loop in main:

// Loop through each turn, ending at 10 moves or a win.
    do {
        
        // Read in the user's guess.
        getUserGuess(board);
        
        // Figure out the number of matches.
        int num_perfect = numPerfectMatches(board, answer);
        int num_imperfect = numWrongPlaceMatches(board, answer);
        
        // Update for this turn.
        printf("You have %d perfect matches and %d imperfect matches.\n", num_perfect, num_imperfect);
        num_turns++;
        
    } while (num_turns < MAX_TURNS && numPerfectMatches(board, answer) < NUM_PEGS);

Working function:

// Pre-conditions: board and answer are of length NUM_PEGS and store the player's
//                 guess and the correct board, respectively.
// Post-conditions: returns the number of pegs that match at INCORRECT spots
//                  after "erasing" those pegs that match at correct spots.
int numWrongPlaceMatches(int board[], int answer[]) {
   
       
    // Create temporary copies of both boards, since we'll need to make changes
    // to each during this process and we don't want to ruin the original
    // state of either board.
    int i, temp1[5], temp2[5];
    for(i=0; i<NUM_PEGS; i++){
             temp1[i] = board[i];
             temp2[i] = answer[i];
             }
    
   
    // Mark out the spots on the board and answer that match up perfectly.
    for(i=0; i<NUM_PEGS; i++){
              if(board[i] == answer [i]){
                          markOutCorrect(board, answer);
              }
    }
    // Go through the board and try to match each peg on the board to
    // a spot on the answer. Hint: A double loop is needed.
    // Note: Remember to "mark" an answer when a match is found.
    int right, wrong;
    for (i=0; i<NUM_PEGS; i++){
        for(i=0; i<NUM_PEGS; i++){
             if(board[i] == MARKED_BOARD){
                         right++;
             }
        board[i]= temp1[i];
        answer[i] = temp2[i];
        }
     
    }   
 
    wrong = NUM_PEGS - right;
    
    return wrong;     
                         
}

[chrisjg04]

Ok so i figured out that the loop doesn't execute because the value of numPerfectMatches is greater than NUM_PEGS.

Would I be able to alter the value of the function to make it less than NUM_PEGS?

[tabstop]

Ok so i figured out that the loop doesn't execute because the value of numPerfectMatches is greater than NUM_PEGS.

Would I be able to alter the value of the function to make it less than NUM_PEGS?

I'm confused. It's a do-while loop, right? They always execute once.