JAVA - DSF Example

 class Solution {

class Point{

int x ;

int y ;

int steps;

public Point(int x, int y , int steps){

this.x = x;

this.y = y;

this.steps = steps;

}

}

public int shortestPathBinaryMatrix(int[][] grid) {

//BFS //DFS

//BFS -> Shortest path

//DSA : Queue

if(grid[0][0] != 0){

return -1;

}

int [][] moves = new int[][]{{0,-1} , {0,1} , {1,0}, {-1,0} , {-1,-1},{-1, 1},{1,1},{1,-1}};

Stack<Point> queue = new Stack<>();

queue.push(new Point(0 , 0, 1));

grid[0][0] = 1;

int newX = 0;

int newY = 0;

while(! queue.isEmpty()){

Point point = queue.pop();

if(point.x == grid.length -1 && point.y == grid[0].length-1){

return point.steps;

}

for(int i = 0 ;i<8 ; i++){

newX = point.x + moves[i][0];

newY = point.y + moves[i][1];

if( newX >=0 && newY >=0 && newX < grid.length && newY < grid[0].length && grid[newX][newY] == 0){

queue.push(new Point(newX, newY , point.steps +1));

grid[newX][newY] = 1;

}

}

}

return -1;

}

}

/**

grid[i][i+1] = 0 ->

grid[i][i-1] = 0 <-

grid[i-1][i] = 0 A

grid[i+1][i] = 0 V

grid[i-1][i-1] = 0 <- A

grid[i-1][i+1] = 0 <- V

grid[i+1][i+1] = 0 -> V

grid[i+1][i-1] = 0 -> A

*/