design_sql_2408: solved

austingebauer · austingebauer · commit 341ad88727fa · 2025-01-07T21:02:23.000-08:00
diff --git a/design_sql_2408/README.md b/design_sql_2408/README.md
@@ -0,0 +1,3 @@
+# 2408. Design SQL
+
+https://leetcode.com/problems/design-sql/description/
diff --git a/design_sql_2408/solution.go b/design_sql_2408/solution.go
@@ -0,0 +1,85 @@
+package design_sql_2408
+
+import (
+	"fmt"
+	"strings"
+)
+
+type table struct {
+	idInc    int
+	colCount int
+	rows     map[int][]string
+}
+
+type SQL struct {
+	tables map[string]*table
+}
+
+func Constructor(names []string, columns []int) SQL {
+	sql := SQL{
+		tables: make(map[string]*table),
+	}
+	for i, name := range names {
+		colCount := columns[i]
+		sql.tables[name] = &table{
+			idInc:    0,
+			colCount: colCount,
+			rows:     make(map[int][]string),
+		}
+	}
+
+	return sql
+}
+
+func (q *SQL) Ins(name string, row []string) bool {
+	table, ok := q.tables[name]
+	if !ok || len(row) != table.colCount {
+		return false
+	}
+
+	table.idInc++
+	table.rows[table.idInc] = row
+	return true
+}
+
+func (q *SQL) Rmv(name string, rowId int) {
+	table, ok := q.tables[name]
+	if !ok {
+		return
+	}
+
+	// deletes are idempotent, no need to check if it exists or not
+	delete(table.rows, rowId)
+}
+
+func (q *SQL) Sel(name string, rowId int, columnId int) string {
+	table, ok := q.tables[name]
+	if !ok {
+		return "<null>"
+	}
+
+	row, ok := table.rows[rowId]
+	if !ok {
+		return "<null>"
+	}
+
+	if columnId < 1 || columnId > len(row) {
+		return "<null>"
+	}
+
+	return row[columnId-1]
+}
+
+func (q *SQL) Exp(name string) []string {
+	table, ok := q.tables[name]
+	if !ok {
+		return []string{}
+	}
+
+	rows := make([]string, 0, len(table.rows))
+	for id, row := range table.rows {
+		rows = append(rows, fmt.Sprintf("%d,%s", id, strings.Join(row, ",")))
+	}
+
+	return rows
+}

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+# 2408. Design SQL`
	`2`	`+`
	`3`	`+https://leetcode.com/problems/design-sql/description/`