s0036

src/s0036_valid_sudoku.cpp

@@ -0,0 +1,38 @@
+#include "s0036_valid_sudoku.hpp"
+
+bool Solution::isValidSudoku(vector<vector<char>>& board) {
+  vector<unordered_map<char, int>> rows;
+  vector<unordered_map<char, int>> columns;
+  vector<unordered_map<char, int>> grids;
+  // Initialize vectors
+  for (int i{0}; i < 9; ++i) {
+    rows.push_back(unordered_map<char, int>{});
+    columns.push_back(unordered_map<char, int>{});
+    grids.push_back(unordered_map<char, int>{});
+  }
+  for (int i{0}; i < 9; ++i) {
+    for (int j{0}; j < 9; ++j) {
+      if (board[i][j] == '.') {
+        continue;
+      }
+      if (rows[j].count(board[i][j]) == 1) {
+        return false;
+      } else {
+        rows[j][board[i][j]] = 1;
+      }
+      if (columns[i].count(board[i][j]) == 1) {
+        return false;
+      } else {
+        columns[i][board[i][j]] = 1;
+      }
+      int gridIndex =
+          static_cast<int>(floor(j / 3)) + 3 * static_cast<int>(floor(i / 3));
+      if (grids[gridIndex].count(board[i][j]) == 1) {
+        return false;
+      } else {
+        grids[gridIndex][board[i][j]] = 1;
+      }
+    }
+  }
+  return true;
+}