void pop() {
if(left.empty()) {
while(!right.empty()) {
left.push(right.top());
right.pop();
}
}
left.pop();
}
int top() {
if(left.empty()) {
while(!right.empty()) {
left.push(right.top());
right.pop();
}
}
return left.top();
}
/*省略构造和析构函数*/
void push (int anum) {
right.push(anum);
}
double Utils::evaluate(QString exp)
{
auto priority = [](QChar o){
switch (o.unicode())
{
case '(':
return 1;
case '+':
case '-':
return 2;
case '*':
case '/':
return 3;
case '+' + 128:
case '-' + 128:
return 4;
case ':':
case ':' + 128:
return 5;
default:
return 0;
}
};
exp.remove(' ');
QString pst;
SStack<QChar> opt;
int i = 0;
opt.push('#');
while (i < exp.length()){
if (exp[i].isDigit() || exp[i] == '.'){
pst.append(exp[i]);
}
else{
auto tra = [&](){
pst.append(' ');
while (priority(exp[i]) <= priority(opt.top())){
pst.append(opt.pop());
}
opt.push(exp[i]);
};
int colon = 0;
switch (exp[i].unicode()){
case '(':
opt.push(exp[i]);
break;
case ')':
while (opt.top() != '('){
pst.append(opt.pop());
}
opt.pop();
break;
case '+':
case '-':
{
if ((i == 0 || (!exp[i - 1].isDigit() && exp[i - 1] != ')')) && (i + 1) < exp.length() && (exp[i + 1].isDigit() || exp[i + 1] == '(')){
exp[i].unicode() += 128;
}
tra();
break;
}
case ':':
switch (colon++){
case 2:
exp[i].unicode() += 128;
case 1:
case 0:
break;
default:
throw std::runtime_error("colon overflow");
}
tra();
break;
case '*':
case '/':
tra();
break;
default:
throw std::runtime_error("token unrecognized");
}
}
++i;
}
while (!opt.isEmpty()){
pst.append(opt.pop());
}
SStack<double> num;
i = 0;
while (pst[i] != '#'){
if (pst[i].isDigit() || pst[i] == '.'){
double n = 0;
while (pst[i].isDigit()){
n = n * 10 + pst[i++].toLatin1() - '0';
}
if (pst[i] == '.'){
++i;
double d = 1;
while (pst[i].isDigit()){
n += (d /= 10)*(pst[i++].toLatin1() - '0');
}
}
num.push(n);
}
else{
switch (pst[i].unicode()){
case '+' + 128:
num.push(+num.pop());
break;
case '-' + 128:
num.push(-num.pop());
break;
case '+':
{
double r = num.pop(), l = num.pop();
num.push(l + r);
break;
}
case '-':
{
double r = num.pop(), l = num.pop();
num.push(l - r);
break;
}
case '*':
{
double r = num.pop(), l = num.pop();
num.push(l*r);
break;
}
case '/':
{
double r = num.pop(), l = num.pop();
num.push(l / r);
break;
}
case ':':
{
double r = num.pop(), l = num.pop();
num.push(l * 60 + r);
break;
}
case ':' + 128:
{
double r = num.pop(), l = num.pop();
num.push(l * 24 + r);
break;
}
}
i++;
}
}
return num.top();
}