cs: add “2352. Equal Row and Column Pairs”

Signed-off-by: Matej Focko <mfocko@redhat.com>

cs/equal-row-and-column-pairs.cs

@@ -0,0 +1,24 @@
+public class Solution {
+    public int EqualPairs(int[][] grid) {
+        var count = 0;
+        var n = grid.Length;
+
+        // Check each row ‹r› against each column ‹c›.
+        for (var r = 0; r < n; ++r) {
+            for (var c = 0; c < n; ++c) {
+                var match = true;
+
+                for (var i = 0; i < n; ++i) {
+                    if (grid[r][i] != grid[i][c]) {
+                        match = false;
+                        break;
+                    }
+                }
+
+                count += match ? 1 : 0;
+            }
+        }
+
+        return count;
+    }
+}