Create Valid Sudoku.java

varunu28 · web-flow · commit 4e179ac0748d · 2019-11-20T06:10:03.000-08:00
diff --git a/Medium/Valid Sudoku.java b/Medium/Valid Sudoku.java
@@ -0,0 +1,27 @@
+class Solution {
+    public boolean isValidSudoku(char[][] board) {
+        HashSet<Character>[] rowSet = new HashSet[9];
+        HashSet<Character>[] colSet = new HashSet[9];
+        HashSet<Character>[] boxSet = new HashSet[9];
+        for (int i = 0; i < 9; i++) {
+            rowSet[i] = new HashSet<>();
+            colSet[i] = new HashSet<>();
+            boxSet[i] = new HashSet<>();
+        }
+        for (int i = 0; i < 9; i++) {
+            for (int j = 0; j < 9; j++) {
+                if (board[i][j] != '.') {
+                    char val = board[i][j];
+                    int boxIdx = (i / 3) * 3 + j / 3;
+                    if (rowSet[i].contains(val) || colSet[j].contains(val) || boxSet[boxIdx].contains(val)) {
+                        return false;
+                    }
+                    rowSet[i].add(val);
+                    colSet[j].add(val);
+                    boxSet[boxIdx].add(val);
+                }
+            }
+        }
+        return true;
+    }
+}
