add 3242

Author: fishercoder1534

Diff for: paginated_contents/algorithms/4th_thousand/README.md

@@ -1,6 +1,7 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
 | 3243 | [Shortest Distance After Road Addition Queries I](https://leetcode.com/problems/shortest-distance-after-road-addition-queries-i/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3243.java) |                                                                               | Medium     |
+| 3242 | [Design Neighbor Sum Service](https://leetcode.com/problems/design-neighbor-sum-service/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3242.java) |                                                                               | Easy       |
 | 3241 | [Time Taken to Mark All Nodes](https://leetcode.com/problems/time-taken-to-mark-all-nodes/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3241.java) |                                                                               | Hard       |
 | 3240 | [Minimum Number of Flips to Make Binary Grid Palindromic II](https://leetcode.com/problems/minimum-number-of-flips-to-make-binary-grid-palindromic-ii/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3240.java) |                                                                               | Medium     |
 | 3239 | [Minimum Number of Flips to Make Binary Grid Palindromic I](https://leetcode.com/problems/minimum-number-of-flips-to-make-binary-grid-palindromic-i/)                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3239.java) |                                                                               | Easy       |

Diff for: src/main/java/com/fishercoder/solutions/fourththousand/_3242.java

@@ -0,0 +1,60 @@
+package com.fishercoder.solutions.fourththousand;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class _3242 {
+    public static class Solution1 {
+        class neighborSum {
+            int[][] matrix;
+            int m;
+            int n;
+            Map<Integer, int[]> map;
+
+            public neighborSum(int[][] grid) {
+                this.matrix = grid;
+                this.m = grid.length;
+                this.n = grid[0].length;
+                this.map = new HashMap<>();
+                for (int i = 0; i < m; i++) {
+                    for (int j = 0; j < n; j++) {
+                        map.put(grid[i][j], new int[]{i, j});
+                    }
+                }
+            }
+
+            public int adjacentSum(int value) {
+                int[] dirs = new int[]{0, 1, 0, -1, 0};
+                int[] pos = this.map.get(value);
+                int sum = 0;
+                for (int i = 0; i < dirs.length - 1; i++) {
+                    int nextx = pos[0] + dirs[i];
+                    int nexty = pos[1] + dirs[i + 1];
+                    if (nextx >= 0 && nextx < m && nexty >= 0 && nexty < n) {
+                        sum += matrix[nextx][nexty];
+                    }
+                }
+                return sum;
+            }
+
+            public int diagonalSum(int value) {
+                int[][] dirs = new int[][]{
+                        {-1, 1},
+                        {1, 1},
+                        {1, -1},
+                        {-1, -1}
+                };
+                int[] pos = this.map.get(value);
+                int sum = 0;
+                for (int[] dir : dirs) {
+                    int nextx = pos[0] + dir[0];
+                    int nexty = pos[1] + dir[1];
+                    if (nextx >= 0 && nextx < m && nexty >= 0 && nexty < n) {
+                        sum += matrix[nextx][nexty];
+                    }
+                }
+                return sum;
+            }
+        }
+    }
+}