Added the Flood-fill algorithm

Flood_Fill.cpp

@@ -0,0 +1,58 @@
+/*
+ * Author : Umesh Kumar
+ * Date : 06/10/2021
+ * Problem : https://leetcode.com/problems/flood-fill/
+ */
+#include <bits/stdc++.h>
+#include <iostream>
+using namespace std;
+
+void dfs(vector<vector<int>> &img, int sr, int sc, int src, int newColor)
+{
+    if (img[sr][sc] != src)
+        return;
+
+    img[sr][sc] = newColor;
+    // top
+    if (sr - 1 >= 0)
+        dfs(img, sr - 1, sc, src, newColor);
+    // bottom
+    if (sr + 1 < img.size())
+        dfs(img, sr + 1, sc, src, newColor);
+    // left
+    if (sc - 1 >= 0)
+        dfs(img, sr, sc - 1, src, newColor);
+    // right
+    if (sc + 1 < img[0].size())
+        dfs(img, sr, sc + 1, src, newColor);
+}
+vector<vector<int>> floodFill(vector<vector<int>> &image, int sr, int sc, int newColor)
+{
+    // if src == newColor, then all the associated grid will of same then no change
+    if (image[sr][sc] == newColor)
+        return image;
+    dfs(image, sr, sc, image[sr][sc], newColor);
+    return image;
+}
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(nullptr);
+    cout.tie(nullptr);
+    vector<vector<int>> image = {{1, 1, 1}, {1, 1, 0}, {1, 0, 1}};
+    int sr = 1, sc = 1, newColor = 2;
+    for (auto e : floodFill(image, sr, sc, newColor))
+    {
+        for (auto a : e)
+            cout << a << " ";
+        cout << endl;
+    }
+    image = {{0, 0, 0}, {0, 0, 0}}, sr = 0, sc = 0, newColor = 2;
+    for (auto e : floodFill(image, sr, sc, newColor))
+    {
+        for (auto a : e)
+            cout << a << " ";
+        cout << endl;
+    }
+    return 0;
+}