Go: package main

import (
	"bufio"
	"fmt"
	"go/token"
	"go/types"
	"os"
	"strconv"
	"strings"
)

func main() {
	stdin := bufio.NewScanner(os.Stdin)
	stdin.Scan()
	n, _ := strconv.Atoi(stdin.Text())
	for i := 0; i < n; i++ {
		stdin.Scan()
		exp := strings.TrimRight(stdin.Text(), "=")
		res, _ := types.Eval(token.NewFileSet(), nil, token.NoPos, exp)
		fmt.Println(res.Value)
	}
}

Python: def ReversePolishNotation(string):

    priority = {"Sentinel": 0, "(": 0, "+": 1, "-": 1, "*": 2, "/": 2}

    stack = []
    signStack = ["Sentinel"]
    isContinue = False

    for item in string[:-1]:
        if str.isnumeric(item):
            if not isContinue:
                stack.append(item)
                isContinue = True
            else:
                stack[-1] += item
            continue
        elif item == "(":
            signStack.append(item)
        elif item == ")":
            while signStack[-1] != "(":
                stack.append(signStack.pop())
            signStack.pop()
        else:
            if priority[signStack[-1]] < priority[item]:
                signStack.append(item)
            else:
                top = signStack.pop()
                stack.append(top)
                signStack.append(item)
        isContinue = False

    while signStack[-1] != "Sentinel":
        stack.append(signStack.pop())

    return stack


def Calculate(formulaList):

    signs = ["+", "-", "*", "/"]

    stack = []

    for item in formulaList:

        if item not in signs:
            stack.append(item)
        else:
            num1 = int(stack.pop())
            num2 = int(stack.pop())

            result = 0

            if item == "+":
                result = num2 + num1
            elif item == "-":
                result = num2 - num1
            elif item == "*":
                result = num2 * num1
            else:
                result = num2 / num1 // 1

            stack.append(result)

    return int(stack[0])


inputCount = int(input())

for lp in range(inputCount):
    formula = input()

    rpn = ReversePolishNotation(formula)
    answer = Calculate(rpn)

    print(str(answer))

Python: from collections import deque

def eva(l, r, op):
    if op == "+":
        return l + r
    elif op == "-":
        return l - r
    elif op == "*":
        return l * r
    elif op == "/":
        return l // r


def calc(exp):
    i = 0
    num = deque()
    ops = deque()
    ope = ""
    while i < len(exp):
        if exp[i] == '(':
            end = 1
            s = 1
            while True:
                if exp[i+end] == "(":
                    s += 1
                elif exp[i+end] == ")":
                    s -= 1
                if s == 0:
                    break
                end += 1
            num.append(calc(exp[i+1:i+end]))
            i += end
            if ope:
                l = num.pop()
                r = num.pop()
                num.append(eva(l, r, ope))
                ope = ""
        if exp[i] in ["*", "/"]:
            ope = exp[i]
        elif exp[i] in ["+", "-"]:
            ops.append(exp[i])
        elif exp[i] == "=":
            pass
        else:
            temp = ""
            j = 0
            while i + j < len(exp) and exp[i+j].isnumeric():
                temp += exp[i+j]
                j += 1
            num.append(int(temp))
            i += j - 1
            if ope:
                num.append(eva(num.pop(), num.pop(), ope))
                ope = ""
        i += 1
    while len(ops) != 0:
        l = num.popleft()
        r = num.popleft()
        num.appendleft(eva(l,r,ops.popleft()))
    
    return num[0]


n = int(input())
for i in range(n):
    exp = input()
    print(calc(exp))

# N = int(input())
# for i in range(N):
#     print(int(eval(input().replace("/", "//").strip("="))))

Python: def ReversePolishNotation(string):

    priority = {"(": 0, ")": 0, "+": 1, "-": 1, "*": 2, "/": 2}

    stack = []
    signStack = []
    isContinue = False

    for item in string[:-1]:

        if str.isnumeric(item):
            if not isContinue:
                stack.append(item)
                isContinue = True
            else:
                stack[-1] += item
            continue
        elif item == "(":
            signStack.append(item)
        elif item == ")":
            while signStack[-1] != "(":
                stack.append(signStack.pop())
            signStack.pop()
        else:
            while len(signStack) != 0 and priority[item] <= priority[signStack[-1]]:
                stack.append(signStack.pop())

            signStack.append(item)

        isContinue = False

    while len(signStack) != 0:
        stack.append(signStack.pop())

    return stack


def Calculate(formulaList):

    signs = ["+", "-", "*", "/"]

    stack = []

    for item in formulaList:

        if item not in signs:
            stack.append(item)
        else:
            num1 = int(stack.pop())
            num2 = int(stack.pop())

            if item == "+":
                result = num2 + num1
            elif item == "-":
                result = num2 - num1
            elif item == "*":
                result = num2 * num1
            else:
                result = num2 / num1 // 1

            stack.append(result)

    return int(stack[0])


inputCount = int(input())

for lp in range(inputCount):
    formula = input()

    rpn = ReversePolishNotation(formula)
    answer = Calculate(rpn)

    print(answer)

Python: from collections import deque
def eva(l, r, op):
    if op == "+":
        return l + r
    elif op == "-":
        return l - r
    elif op == "*":
        return l * r
    elif op == "/":
        return l // r


def calc(exp):
    i = 0
    num = deque()
    ops = deque()
    ope = ""
    while i < len(exp):
        if exp[i] == '(':
            end = exp[i:].rfind(")")
            num.append(calc(exp[i+1:i+end]))
            i += end + 1
            if ope:
                l = num.pop()
                r = num.pop()
                num.append(eva(l, r, ope))
                ope = ""
        elif exp[i].isnumeric():
            num.append(int(exp[i]))
            if ope:
                num.append(eva(num.pop(), num.pop(), ope))
                ope = ""
        elif exp[i] in ["*", "/"]:
            ope = exp[i]
        elif exp[i] in ["+", "-"]:
            ops.append(exp[i])
        elif exp[i] == "=":
            break
        i += 1
    while len(ops) != 0:
        l = num.popleft()
        r = num.popleft()
        num.appendleft(eva(l,r,ops.popleft()))
    return num[0]


n = int(input())
for i in range(n):
    exp = input()
    print(calc(exp))

Python: import sys
#from me.io import dup_file_stdin

#@dup_file_stdin
def solve():
    for _ in range(int(sys.stdin.readline())):
        print(eval(sys.stdin.readline()[:-2].replace(r"/",r"//")))
 
solve()

Python: # Aizu Problem 0109: Smart Calculator

#
import sys, math, os

# read input:
PYDEV = os.environ.get('PYDEV')
if PYDEV=="True":
    sys.stdin = open("sample-input.txt", "rt")


N = int(input())
for _ in range(N):
    print(eval(input().replace('=', '').replace('/', '//')))

Python: # -*- coding: utf-8 -*-

import sys
import os
import math
import re

class Num:
    def __str__(self):
        return str(self.x)

    def __init__(self, value):
        self.x = value

    def __add__(self,value):
        return Num(self.x + value.x)

    def __sub__(self, value):
        return Num(self.x - value.x)

    def __mul__(self, value):
        return Num(self.x * value.x)

    def __truediv__(self,value):
        return Num(math.ceil(self.x / value.x))

n = int(input())

for i in range(n):
    command = input().strip()
    command = command.replace('=', '')
    command = re.sub(r'(\d+)', r'Num(\1)', command)
    print(eval(command))

# Supplement
# -1 // 2 => -1