solves #2614: PrimeInDiagonal in java

Author: anishLearnsToCode

README.md

@@ -812,7 +812,7 @@
 | 2600 | [K Items With the Maximum Sum](https://leetcode.com/problems/k-items-with-the-maximum-sum)                                                                             |                                                                                   [![Java](assets/java.png)](src/KItemsWithTheMaximumSum.java)                                                                                   |                                                                                                                                   |
 | 2605 | [Form Smallest Number From Two Digit Arrays](https://leetcode.com/problems/form-smallest-number-from-two-digit-arrays)                                                 |                                                                            [![Java](assets/java.png)](src/FormSmallestNumberFromTwoDigitArrays.java)                                                                             |                                                                                                                                   |
 | 2609 | [Find the Longest Balanced Substring of a Binary String](https://leetcode.com/problems/find-the-longest-balanced-substring-of-a-binary-string)                         |                                                                       [![Java](assets/java.png)](src/FindTheLongestBalancedSubstringOfABinaryString.java)                                                                        |                                                                                                                                   |
-| 2614 | [Prime In Diagonal](https://leetcode.com/problems/prime-in-diagonal)                                                                                                   |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2614 | [Prime In Diagonal](https://leetcode.com/problems/prime-in-diagonal)                                                                                                   |                                                                                       [![Java](assets/java.png)](src/PrimeInDiagonal.java)                                                                                       |                                                                                                                                   |
 | 2639 | [Find the Width of Columns of a Grid](https://leetcode.com/problems/find-the-width-of-columns-of-a-grid)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2643 | [Row With Maximum Ones](https://leetcode.com/problems/row-with-maximum-ones)                                                                                           |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2644 | [Find the Maximum Divisibility Score](https://leetcode.com/problems/find-the-maximum-divisibility-score)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/PrimeInDiagonal.java

@@ -0,0 +1,37 @@
+// https://leetcode.com/problems/prime-in-diagonal
+// m: number of rows in matrix
+// n: size of numbers in matrix
+// T: O(m * sqrt(n))
+// S: O(1)
+
+public class PrimeInDiagonal {
+    public int diagonalPrime(int[][] nums) {
+        final int rows = nums.length;
+        int maxPrime = 0;
+        // left to right diagonal
+        for (int row = 0 ; row < rows ; row++) {
+            if (row % 2 == 1 && row == rows / 2) {
+                continue;
+            }
+            if (isPrime(nums[row][row])) {
+                maxPrime = Math.max(maxPrime, nums[row][row]);
+            }
+        }
+
+        // top right to bottom left diagonal
+        for (int row = 0 ; row < rows ; row++) {
+            if (isPrime(nums[row][rows - row - 1])) {
+                maxPrime = Math.max(maxPrime, nums[row][rows - row - 1]);
+            }
+        }
+        return maxPrime;
+    }
+
+    private boolean isPrime(int x) {
+        if (x <= 1) return false;
+        for (int i = 2 ; i * i <= x ; i++) {
+            if (x % i == 0) return false;
+        }
+        return true;
+    }
+}