供参考
int main()
{
vector<int> input;
int a, b, result = 0;
char str[100];
cin.getline(str, 100);
char *s = strtok(str, " ");
while (s != NULL && *s != '@')
{
if (isdigit(*s))
{
result = atoi(s);
input.push_back(result);
}
else
{
b = input.back();
input.pop_back();
a = input.back();
switch (*s)
{
case '+':
result = a + b;
break;
case '-':
result = a - b;
break;
case '*':
result = a * b;
break;
case '/':
result = a / b;
break;
}
input.pop_back();
input.push_back(result);
}
s = strtok(NULL, " ");
}
cout << result << endl;
return 0;
}