Update 0150.逆波兰表达式求值.md

problems/0150.逆波兰表达式求值.md

@@ -170,7 +170,32 @@ public class EvalRPN {
 
 }
 ```
-
+Go:
+```Go
+func evalRPN(tokens []string) int {
+	stack := []int{}
+	for _, token := range tokens {
+		val, err := strconv.Atoi(token)
+		if err == nil {
+			stack = append(stack, val)
+		} else {
+			num1, num2 := stack[len(stack)-2], stack[(len(stack))-1]
+			stack = stack[:len(stack)-2]
+			switch token {
+			case "+":
+				stack = append(stack, num1+num2)
+			case "-":
+				stack = append(stack, num1-num2)
+			case "*":
+				stack = append(stack, num1*num2)
+			case "/":
+				stack = append(stack, num1/num2)
+			}
+		}
+	}
+	return stack[0]
+}
+```