Question

Using C++

In a paint program, a “flood fill” fills all empty pixels of a drawing with a given color, stopping when it reaches occupied pixels. In this exercise, you will implement a simple variation of this algorithm, flood-filling a 10 × 10 array of integers that are initially 0.

Prompt for the starting row and column.

Push the (row, column) pair on a stack.

You will need to provide a simple Pair class.

Repeat the following operations until the stack is empty:

Pop off the (row, column) pair from the top of the stack.

If it has not yet been filled, fill the corresponding array location with numbers 1, 2, 3, and so on (to show the order in which the square is filled.)

Push the coordinates of any unfilled neighbors in the north, east, south, or west direction on the stack.

When you are done, print the entire array.

Answer 1

Given below is the code for the question. Please do rate the answer if it helped. Thank you.

#include <iostream>
#include <iomanip>
using namespace std;
const int MAX_ROWS = 10;
const int MAX_COLS = 10;
struct Pair
{
   int row;
   int col;
   Pair(int r = 0, int c = 0){
       row = r;
       col = c;
   }
};

class Stack
{
   private:
       Pair data[MAX_ROWS*MAX_COLS];
       int top;
   public:
       Stack()
       {
           top = 0;
       }
       void push(Pair p){
           data[top] = p;
           top++;
       }
      
       bool empty(){
           return top == 0;
       }
      
       Pair pop(){
           return data[--top];
       }
};

bool isColored(int pixels[][MAX_COLS], Pair p){
   if(pixels[p.row][p.col] != 0)
       return true;
   else
       return false;
}

bool isValid(Pair p){
   if(p.row >= 0 && p.row < MAX_ROWS && p.col >= 0 && p.col < MAX_COLS)
       return true;
   else
       return false;
}

int main(){
   Stack s;
   int pixels[MAX_ROWS][MAX_COLS] = {0};
   int row, col, count = 1;
   Pair p;
  
   cout << "Enter starting row (0-9): ";
   cin >> row;
   cout << "Enter starting column (0-9): ";
   cin >> col;
   s.push(Pair(row, col));
   while(!s.empty()){
       p = s.pop();
       if(!isColored(pixels, p)){
           pixels[p.row][p.col] = count;
           count++;
       }
      
       Pair north(p.row-1, p.col);
       Pair east(p.row, p.col +1 );
       Pair south(p.row+1, p.col);
       Pair west(p.row, p.col-1);
      
       if(isValid(north) && !isColored(pixels, north))
           s.push(north);
       if(isValid(east) && !isColored(pixels, east))
           s.push(east);
       if(isValid(south) && !isColored(pixels, south))
           s.push(south);
       if(isValid(west) && !isColored(pixels, west))
           s.push(west);
      
   }
  
  
   //display the pixel numbering
   for(int i = 0; i < MAX_ROWS; i++){
       for(int j = 0; j < MAX_COLS; j++){
           cout << setw(5) << pixels[i][j];
       }
       cout << endl;
   }
   return 0;
}