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)
	}
}

C++: #include <bits/stdc++.h>
#include<stdio.h>
using namespace std;
#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(a) begin(a),end(a)
#define MS(m,v) memset(m,v,sizeof(m))
#define D10  fixed<<setprecision(10)
typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int, int> P;
typedef long long ll;
const ll INF = 114514810;
const ll MOD = 1000000007;
const double EPS = 1e-8;
const double PI = acos(-1.0);
struct edge
{
	int to, cost;
	bool operator < (const edge& e) const { return cost < e.cost; }
	bool operator >(const edge& e) const { return cost > e.cost; }
};
int dx[] = { -1, 0, 0, 1 }; int dy[] = { 0, -1, 1, 0 };
bool valid(int x, int y, int h, int w) { return (x >= 0 && y >= 0 && x < h&&y < w); }
///*************************************************************************************///
///*************************************************************************************///
///*************************************************************************************///

string s;
int p;

int solve();

int elem()
{
	if (s[p] == '(')
	{
		p++;
		int buf = solve();
		p++;
		return buf;
	}
	int res = 0;
	while (isdigit(s[p]))
	{
		res = res * 10 + (s[p] - '0');
		p++;
	}
	return res;
}

int term()
{
	int tmp = elem();
	while (s[p] == '*' || s[p] == '/')
	{
		char c = s[p];
		p++;
		if (c == '*') tmp *= elem();
		else tmp /= elem();
	}
	return tmp;
}

int solve()
{
	int tmp = term();
	while (s[p] == '+' || s[p] == '-')
	{
		char c = s[p];
		p++;
		if (c == '+') tmp += term();
		else tmp -= term();
	}
	return tmp;
}

int main()
{
	int n;
	cin >> n;

	while (n--)
	{
		p = 0;
		cin >> s;
		s.pop_back();
		cout << solve() << endl;
	}
	return 0;
}

C++: //https://gist.github.com/draftcode/1357281
#include <string>
#include <cctype>
#include <iostream>
typedef std::string::iterator State;
class ParseError {};

int number(State &begin);
int factor(State &begin);
int term(State &begin);
int expression(State &begin);
void consume(State &begin, char expected){
	if(*begin == expected){
		begin++;
	}else{
		std::cerr << "Expected '" << expected << "' but got '"<<*begin << "'"<<std::endl;
		std::cerr << "Rest string is '";
		while(*begin){
			std::cerr << *begin++;
		}
		std::cerr<<"'"<<std::endl;
		throw ParseError();
	}
}

int main(void){
	int N;
	std::cin >> N;
	std::cin.ignore();
	for(int i = 0; i < N; ++i){
		std::string s;
		std::getline(std::cin, s);
		State begin = s.begin();
		int ans = expression(begin);
		consume(begin, '=');
		std::cout << ans << std::endl;
	}
	return 0;
}

int number(State &begin){
	int ret = 0;

	while(isdigit(*begin)){
		ret *= 10;
		ret += *begin - '0';
		begin++;
	}

	return ret;
}

int factor(State &begin){
	if(*begin == '('){
		consume(begin,'(');
		int ret = expression(begin);
		consume(begin,')');
	}else{
		return number(begin);
	}
}

int term(State &begin){
	int ret = factor(begin);

	for(;;){
		if(*begin == '*'){
			begin++;
			ret *= factor(begin);
		}else if(*begin == '/'){
			begin++;
			ret /= factor(begin);
		}else{
			break;
		}
	}
	return ret;
}

int expression(State &begin){
	int ret = term(begin);

	for(;;){
		if(*begin == '+'){
			begin++;
			ret += term(begin);
		} else if(*begin == '-'){
			begin++;
			ret -= term(begin);
		}else {
			break;
		}
	}
	return ret;
}