Coding Interviews Spiral Code Solution

spiral.cpp

int * spiral(int r, int c, int sr, int sc) {
	//Traverse direction increment state and direction state
	// %4 == 1 -> north; 2 -> east; 3 -> south; 0 -> west;
	int *array = new int [r*c];
	int counter = 1, steps, dir, increment, arridx = 0;
	bool vertical = true;
	array[arridx++] = matrix[sr-1][sc-1];
	while(arridx < r*c) {
		dir = counter % 4;
		vertical = dir == 1 || dir == 3 ? true : false;
		if (vertical)
			increment = dir == 1 ? -1 : 1;
		else
			increment = dir == 0 ? 1 : -1;
		for (int i = 0; i < (counter+1)/2; i++) {
			if (vertical)
				sr += increment;
			else
				sc += increment;
			if (sr <= r && sr >= 1 && sc <= c && sc >= 1) {
				array[arridx++] = matrix[sr-1][sc-1];
			}
		}
		counter++;
	}
	return array;
}