adding the Flood fill in Java and CPP

.vscode/tasks.json

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+{
+    "tasks": [
+        {
+            "type": "cppbuild",
+            "label": "C/C++: g++.exe build active file",
+            "command": "C:\\MinGW\\bin\\g++.exe",
+            "args": [
+                "-fdiagnostics-color=always",
+                "-g",
+                "${file}",
+                "-o",
+                "${fileDirname}\\${fileBasenameNoExtension}.exe"
+            ],
+            "options": {
+                "cwd": "${fileDirname}"
+            },
+            "problemMatcher": [
+                "$gcc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "detail": "Task generated by Debugger."
+        }
+    ],
+    "version": "2.0.0"
+}

C++/FloodFillDFS.cpp

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+#include <iostream>
+#include <vector>
+using namespace std;
+
+class FloodFillDFS {
+public:
+    void floodFill(vector<vector<int>>& image, int sr, int sc, int newColor) {
+        int oldColor = image[sr][sc];
+        if (oldColor == newColor) return;
+        dfs(image, sr, sc, oldColor, newColor);
+    }
+
+    void dfs(vector<vector<int>>& image, int r, int c, int oldColor, int newColor) {
+        // Boundary check
+        if (r < 0 || c < 0 || r >= static_cast<int>(image.size()) || c >= static_cast<int>(image[0].size()))
+            return;
+
+        // Stop if color does not match
+        if (image[r][c] != oldColor)
+            return;
+
+        // Replace color
+        image[r][c] = newColor;
+
+        // Explore neighbors
+        dfs(image, r + 1, c, oldColor, newColor);
+        dfs(image, r - 1, c, oldColor, newColor);
+        dfs(image, r, c + 1, oldColor, newColor);
+        dfs(image, r, c - 1, oldColor, newColor);
+    }
+};
+
+int main() {
+    vector<vector<int>> image = {
+        {1, 1, 1},
+        {1, 1, 0},
+        {1, 0, 1}
+    };
+
+    FloodFillDFS solver;
+    solver.floodFill(image, 1, 1, 2);
+
+    // Print output
+    for (auto& row : image) {
+        for (int val : row) {
+            cout << val << " ";
+        }
+        cout << endl;
+    }
+
+    return 0;
+}

README_FLOOD_FILL.md

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+## Flood Fill Algorithm (LeetCode 733)
+
+- Uses DFS to fill connected cells of the same color.
+- Time: O(R × C)
+- Space: O(R × C)

java/FloodFillDFS.java

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+public final class FloodFillDFS {
+
+    private FloodFillDFS() {
+        // Utility class; prevent instantiation.
+    }
+    public static void main(String[] args) {
+        int[][] image = {
+            {1, 1, 1},
+            {1, 1, 0},
+            {1, 0, 1}
+        };
+
+        floodFill(image, 1, 1, 2);
+
+        for (int[] row : image) {
+            for (int val : row) {
+                System.out.print(val + " ");
+            }
+            System.out.println();
+        }
+    }
+
+    static void floodFill(int[][] image, int sr, int sc, int newColor) {
+        int oldColor = image[sr][sc];
+        if (oldColor == newColor) return;
+        dfs(image, sr, sc, oldColor, newColor);
+    }
+
+    static void dfs(int[][] image, int r, int c, int oldColor, int newColor) {
+        if (r < 0 || c < 0 || r >= image.length || c >= image[0].length) return;
+        if (image[r][c] != oldColor) return;
+
+        image[r][c] = newColor;
+
+        dfs(image, r + 1, c, oldColor, newColor);
+        dfs(image, r - 1, c, oldColor, newColor);
+        dfs(image, r, c + 1, oldColor, newColor);
+        dfs(image, r, c - 1, oldColor, newColor);
+    }
+}