Untitled

#include <iostream>
#include <vector>
#include <cstring>
using namespace std;

bool isCurrentCellSafe(int x, int y, int n, vector<vector<int> > &maze){
	
	return  !(x < 0 || y < 0 || x >=n || y>=n || maze[x][y] == 0);
}

void countUniqueHelper(vector<vector<int> > &maze, int x, int y, pair<int, int> &dest, 
vector<vector<bool> > &visited, int &count){
	
	if(x == dest.first && y == dest.second){
		count++;
		return;
	}
	
	visited[x][y] = 1;
	int n = maze.size();
	
	if(isCurrentCellSafe(x, y, n, maze)){
		
		// 1. kya visited of x+1 is not 1
		if(x + 1 < n && !visited[x+1][y]) {
			countUniqueHelper(maze, x+1, y, dest, visited, count);
		}
		
		if(x - 1 >= 0 && !visited[x-1][y]) countUniqueHelper(maze, x-1, y, dest, visited, count);
		
		if(y + 1 < n && !visited[x][y+1]) countUniqueHelper(maze, x, y+1, dest, visited, count);
		
		if(y - 1 >= 0 && !visited[x][y-1]) countUniqueHelper(maze, x, y-1, dest, visited, count);
	}
	
	visited[x][y] = 0;
	
}

int countUniquePaths(vector<vector<int> > &maze, pair<int, int> &source, pair<int, int> &dest){
	
	// conditions for the source cell
	// 1. you can't go beyond the maze - i<0 , i>r, j<0, j>c
	// 2. you can't go blocked cell - if maze[i][j] == 0
	// 3. you can't revisit a cell - visited matrix
	
	int n = maze.size(); // number of rows
	
	int count = 0;
	
	vector<vector<bool> > visited; 
	visited.resize(n, vector<bool>(n)); // false
	
	int currX = source.first;
	int currY = source.second;
	
	countUniqueHelper(maze, currX, currY, dest, visited, count);
	
	return count;
	
	
}

int main() {
	
	vector<vector<int> > maze = 
	{
		{1, 1, 1, 1},
		{1, 1, 0, 1},
		{0, 1, 0, 1},
		{1, 1, 1, 1}
	};
	
	// pairs
	pair<int, int> source = make_pair(0, 0);
	pair<int, int> dest = make_pair(3, 3);
	
	int uniquePaths = countUniquePaths(maze, source, dest);
	cout << uniquePaths << endl;
	
	return 0;
}