733. Flood Fill java

https://leetcode.com/problems/flood-fill/description/

Flood Fill - LeetCode

class Solution {
    int[][] image;
    int m;
    int n;
    int newColor;
    int oldColor;
    boolean [][] visited;
    
    public int[][] floodFill(int[][] image, int sr, int sc, int color) {
        this.m = image.length;
        this.n = image[0].length;
        this.image = image;
        this.oldColor = image[sr][sc];
        this.newColor = color;
        this.visited = new boolean[this.m][this.n];

        dfs(sr, sc);

        return this.image;
    }

    public void dfs(int i, int j) {
        if (go_outside(i, j)) return;
        if (this.visited[i][j]) return;
        this.visited[i][j] = true;

        if (this.image[i][j] != this.oldColor) return;

        this.image[i][j] = this.newColor;

        dfs(i+1, j);
        dfs(i, j+1);
        dfs(i-1, j);
        dfs(i, j-1);
    }

    public boolean go_outside(int i, int j) {
        if (i < 0 || i >= m || j < 0 || j >= n) {
            return true;
        }
        return false;
    }
}