add new solutions

solutions/q36/solution.go

@@ -0,0 +1,63 @@
+package q36
+
+func validateCol(board [][]byte, col int) bool {
+	var present [10]bool
+	for i := range 9 {
+		c := board[i][col]
+		if c != '.' {
+			if present[c-'0'] {
+				return false
+			}
+			present[c-'0'] = true
+		}
+	}
+	return true
+}
+
+func validateRow(board [][]byte, row int) bool {
+	var present [10]bool
+	for i := range 9 {
+		c := board[row][i]
+		if c != '.' {
+			if present[c-'0'] {
+				return false
+			}
+			present[c-'0'] = true
+		}
+	}
+	return true
+}
+
+func validateBox(board [][]byte, box int) bool {
+	xOffset := (box % 3) * 3
+	yOffset := (box / 3) * 3
+
+	var present [10]bool
+	for i := range 9 {
+		x := xOffset + i%3
+		y := yOffset + i/3
+		c := board[y][x]
+		if c != '.' {
+			if present[c-'0'] {
+				return false
+			}
+			present[c-'0'] = true
+		}
+	}
+	return true
+}
+
+func validate(board [][]byte) bool {
+	for i := range 9 {
+		if !validateCol(board, i) || !validateRow(board, i) || !validateBox(board, i) {
+			return false
+		}
+	}
+	return true
+}
+
+func isValidSudoku(board [][]byte) bool {
+	return validate(board)
+}
+
+var _ = isValidSudoku