From 5d21125e56b995896fd255633ae5b957c85446a0 Mon Sep 17 00:00:00 2001
From: Shafaqun Nisa <nisashafaqun@gmail.com>
Date: Fri, 3 Oct 2025 03:36:23 +0530
Subject: [PATCH] 36.Valid Sudoku.cpp

---
 36.Valid Sudoku.cpp | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 36.Valid Sudoku.cpp

diff --git a/36.Valid Sudoku.cpp b/36.Valid Sudoku.cpp
new file mode 100644
index 0000000..7a37a4c
--- /dev/null
+++ b/36.Valid Sudoku.cpp	
@@ -0,0 +1,28 @@
+class Solution {
+public:
+    bool isValidSudoku(vector<vector<char>>& board) {
+        bitset<9> Col[9];
+        bitset<9> Row[9];
+        bitset<9> Block[9];
+
+        for(int i=0; i<9; i++){
+            for(int j=0; j<9; j++){
+                char c = board[i][j];
+                if (c == '.') continue;
+                int x=(c-'0')%9; 
+                // Convert the character digit to an index (0-8) 0 for 9
+
+                if (Row[i][x]) return 0;
+                Row[i][x] = 1;
+
+                if (Col[j][x]) return 0;
+                Col[j][x] = 1;
+                
+                int bidx = (i / 3) * 3 + j / 3;
+                if (Block[bidx][x]) return 0;
+                Block[bidx][x] = 1;
+            }
+        }
+        return 1;
+    }
+};