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 <iostream>
#include <string>
using namespace std;

int n;
string str;
int number(int& i);
int term(int& i);
int expression(int& i);
int factor(int& i);

int number(int& i)
{
	int ret = 0;
	while ('0' <= str[i] && str[i] <= '9')
	{
		ret *= 10;
		ret += str[i] - '0';
		i++;
	}
	return ret;
}

int term(int& i)
{
	int ret = factor(i);
	while (true)
	{
		if (str[i] == '*')
		{
			i++;
			ret *= factor(i);
		}
		else if (str[i] == '/')
		{
			i++;
			ret /= factor(i);
		}
		else
		{
			break;
		}
	}
	return ret;
}

int expression(int& i)
{
	int ret = term(i);
	while (true)
	{
		if (str[i] == '+')
		{
			i++;
			ret += term(i);
		}
		else if (str[i] == '-')
		{
			i++;
			ret -= term(i);
		}
		else
		{
			break;
		}
	}
	return ret;
}

int factor(int& i)
{
	int ret = 0;
	if (str[i] == '(')
	{
		i++;
		ret = expression(i);
		i++;
	}
	else
	{
		ret = number(i);
	}
	return ret;
}

int main()
{
	cin >> n;
	while (n--)
	{
		cin >> str;
		int i = 0;
		cout << expression(i) << endl;
	}
	return 0;
}

C++: #define	_USE_MATH_DEFINES
#include <iostream>
#include <iomanip>
#include <cctype>
#include <algorithm>
#include <functional>
#include <vector>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cfloat>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <string>
#include <set>
#include <complex>
#include <utility>
#include <numeric>
#define  rep(i,n) for(int i=0;i<(n);i++)
#define  REP(i,a,n) for(int i=a;i<(n);i++)
#define  rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define  VI	vector<int>
#define	 VS vector<string>
#define  all(a) (a).begin(),(a).end()
#define  debug(x) cout<<#x<<": "<<x<<endl
using namespace std;
typedef long long ll;
typedef string::const_iterator State;
class ParseError {};
const int INF=1e9;
char fi[101][101];
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
double EPS = 1e-10;
int N,M;
int sx,sy;
int gx,gy;
int w,h;
int ans;
int dx[4]={0,0,-1,1};
int dy[4]={-1,1,0,0};
const int MAX_V=100;
const int MAX_N=100;
char o[3]={'+','-','*'};
#define md 1000003


int dp[353][353]={0};
int bow[353][353]={0};
double add(double a,double b){
	if(abs(a+b)<EPS*(abs(a)+abs(b)))
	return 0;
	return a+b;
}

struct P{
	double x,y;
	P(){}
		P(double x,double y):x(x),y(y){
		}
		P operator + (P p){
			return P(add(x,p.x),add(y,p.y));
		}
		P operator - (P p){
			return P(add(x,-p.x),add(y,-p.y));
		}
		P operator *(double d){
			return P(x*d,y*d);
		}
		double dot(P p){
			return add(x*p.x,y*p.y);
		}
		double det(P p){
			return add(x*p.y,-y*p.x);
		}
};

bool cmp_x(const P& p,const P& q){
	if(p.x!=q.x) return p.x<q.x;
	return p.y<q.y;
}

vector<P> convex_hull(P* ps, int n){
	sort(ps,ps+n,cmp_x);
	int k=0;
	vector<P> 	qs(n*2);
	
	rep(i,n){
		while(k>1&&(qs[k-1]-qs[k-2]).det(ps[i]-qs[k-1])<=0)
			k--;
		qs[k++]=ps[i];
	}
	for(int i=n-2,t=k;i>=0;i--){
		while(k>t&&(qs[k-1]-qs[k-2]).det(ps[i]-qs[k-1])<=0)
		k--;
		qs[k++]=ps[i];
	}
	qs.resize(k-1);
	return qs;
}

int n,m;
vector<double> p;
P ps[101];
char c[520][520];
long long mod=1000000007;
long long pow(ll i,ll j){
	ll tmp=1;
	while(j){
		if(j%2) tmp=tmp*i%mod;
		i=i*i%mod;
		j/=2;
	}
	return tmp;
}
int cards[10];
bool ok;
void saiki(int deep){
	if(deep==4){
		ok=true;
		return;
	}
	for(int i=1;i<=7;i++){
		if(cards[i]>0&&cards[i+1]>0&&cards[i+2]>0){
			cards[i]--;
			cards[i+1]--;
			cards[i+2]--;
			saiki(deep+1);
			cards[i]++;
			cards[i+1]++;
			cards[i+2]++;
		}
		for(int i=1;i<=9;i++){
			if(cards[i]>2){
				cards[i]-=3;
				saiki(deep+1);
				cards[i]+=3;
			}
		}
	}
	
}
int expression(State&);
int term(State&);
int factor(State&);
int number(State&);
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;
}

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

}

int number(State &begin){
	int ret =0;
	
	while(isdigit(*begin)){
		ret*=10;
		ret+=*begin - '0';
		begin++;
	}
	return ret;
}

int main(){
	
	int n;
	cin>>n;
	cin.ignore();
	rep(i,n){
		string s;
		getline(cin,s);
		
		State begin = s.begin();
		int ans = expression(begin);
		cout << ans << endl;
	}
	
	
}

C++: #include<string>
#include<cstdlib>
#include<iostream>

using namespace std;

int prior[128];

int parse(string s)
{
	if(s[0]=='(' && s[s.length()-1]==')'){
		bool f=true;
		for(int i=1,d=1;i<s.length()-1;i++){
			if     (s[i]=='(')	d++;
			else if(s[i]==')')	d--;
			if(d==0){	f=false;	break;	}
		}
		if(f)	return parse(s.substr(1,s.length()-2));
	}

	int divprr=3,divpos=10000000;
	for(int i=0,d=0;i<s.length();i++){
		if     (s[i]=='(')	d++;
		else if(s[i]==')')	d--;

		else if(d==0 && prior[s[i]]!=0){
			if(i==0 && prior[s[i]]==1)	continue;
			if(divprr>prior[s[i]])
				divprr=prior[s[i]],divpos=i;
		}
	}

	if(divpos==10000000)	return atoi(s.c_str());

	switch(s[divpos]){
		case '+': return parse(s.substr(0,divpos)) + parse(s.substr(divpos+1));
		case '-': return parse(s.substr(0,divpos)) - parse(s.substr(divpos+1));
		case '*': return parse(s.substr(0,divpos)) * parse(s.substr(divpos+1));
		case '/': return parse(s.substr(0,divpos)) / parse(s.substr(divpos+1));
	}
}

int main()
{
	prior['+']=prior['-']=1;
	prior['*']=prior['/']=2;

	int n;	cin>>n;
	while(n--){
		string s;	cin>>s;
		s=s.substr(0,s.length()-1);
		cout<<parse(s)<<endl;
	}

	return 0;
}

C++: #include <iostream>
using namespace std;

int hyoka(string);
int isNum(int);

int main(){
	int n,i;
	string s;
	
	cin>>n;
	for(i=0;i<n;i++){
	 cin>>s;
	 cout<<hyoka(s)<<endl;
	}
		
	return 0;
}


int hyoka(string s){
	long int total=0,work=0;
	long int tmp1,tmp2;
	int oi=0;
	char oc;
	int n;
	string cs;
	
	if(isNum(s[oi])!=-1){s="+"+s;}
	
	while(1){
	 oc=s[oi];if(oc=='='){total+=work;break;}
	 
	 if(s[oi+1]!='('){	//??°???????????????
	  tmp1=0;
	  while(1){
	   oi++;
	   tmp2=isNum(s[oi]);
	   if(tmp2!=-1){tmp1=tmp1*10+tmp2;}else{break;}
	  }
	 }else{	//??????????????°
	  cs="";n=1;oi++;
	  while(1){
	   oi++;
	   switch(s[oi]){
		case '(':n++;break;
		case ')':n--;break;
	   }
	   if(n!=0){cs+=s[oi];}else{break;}
	  }
	  cs+='=';
	  tmp1=hyoka(cs);
	 }
	
	 switch(oc){
	  case '+':total+=work;work=tmp1;break;
	  case '-':total+=work;work=-tmp1;break;
	  case '*':work*=tmp1;break;
	  case '/':work/=tmp1;break;
	 }
	}
	
	return total;
}

int isNum(int c){
	if(49<=c && c<=57){
	 return c-49;
	}
	return -1;
}