go: add «1106. Parsing A Boolean Expression»

URL:	https://leetcode.com/problems/parsing-a-boolean-expression/
Signed-off-by: Matej Focko <me@mfocko.xyz>

go/parsing-a-boolean-expression.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	arraystack "github.com/emirpasic/gods/v2/stacks/arraystack"
+)
+
+func parseBoolExpr(expression string) bool {
+	getRune := func(result bool) rune {
+		if result {
+			return 't'
+		}
+		return 'f'
+	}
+
+	st := arraystack.New[rune]()
+
+	for _, token := range expression {
+		if token == ',' || token == '(' {
+			// ignore delimiters and opening brackets
+			continue
+		}
+
+		// Handle closing of the operation
+		if token == ')' {
+			hasTrue, hasFalse := false, false
+
+			for top, has := st.Peek(); has && top != '!' && top != '&' && top != '|'; top, has = st.Peek() {
+				if top == 't' {
+					hasTrue = true
+				} else if top == 'f' {
+					hasFalse = true
+				}
+				st.Pop()
+			}
+
+			// evaluate the operator
+			op, _ := st.Pop()
+			if op == '!' {
+				st.Push(getRune(!hasTrue))
+			} else if op == '&' {
+				st.Push(getRune(!hasFalse))
+			} else {
+				st.Push(getRune(hasTrue))
+			}
+
+			continue
+		}
+
+		st.Push(token)
+	}
+
+	result, _ := st.Peek()
+	return result == 't'
+}