Day5

2022-10-07 00:48:29 +03:00
parent c388b14c3f
commit 0b88604037
20 changed files with 414 additions and 7 deletions
--- a/Sudoku/Solution.cs
+++ b/Sudoku/Solution.cs
@@ -0,0 +1,80 @@
+namespace _36._Valid_Sudoku;
+
+public class Solution
+{
+    public bool IsValidSudoku(char[][] board)
+    {
+        return CheckRows(board) && CheckColumns(board) && CheckSubBoxes(board);
+    }
+
+    private bool CheckRows(char[][] board)
+    {
+        foreach (char[] row in board)
+        {
+            HashSet<char> rowSet = new HashSet<char>();
+            foreach (char c in row)
+            {
+                if(c != '.')
+                {
+                    int prevCount = rowSet.Count;
+                    rowSet.Add(c);
+                    if (prevCount == rowSet.Count)
+                        return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private bool CheckColumns(char[][] board)
+    {
+        for(int columnIndex = 0; columnIndex < board[0].Length; columnIndex++)
+        {
+            HashSet<char> column = new HashSet<char>();
+            for(int rowIndex = 0; rowIndex < board[columnIndex].Length; rowIndex++)
+            {
+                char ch = board[rowIndex][columnIndex];
+                if (ch != '.')
+                {
+                    int prevCount = column.Count;
+                    column.Add(ch);
+                    if (prevCount == column.Count)
+                        return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private bool CheckSubBoxes(char[][] board)
+    {
+        for(int i = 0; i < 27; i+=3)
+        {
+            int y = i / 9 * 3;
+            int x = i % 9;
+            if (CheckSubBox(board, y, x) == false)
+                return false;
+        }
+        return true;
+    }
+
+    private bool CheckSubBox(char[][] board, int startY, int startX)
+    {
+        HashSet<char> set = new HashSet<char>();
+        for (int y = startY; y < startY+3; y++)
+        {
+            for(int x = startX; x < startX+3; x++)
+            {
+                char ch = board[y][x];
+                if(ch!='.')
+                {
+                    int prev = set.Count;
+                    set.Add(ch);
+                    if (prev == set.Count)
+                        return false;
+                }
+            }
+        }
+        return true;
+    }
+}