计算机考研复试真题 计算表达式

/**/
#include<iostream>
using namespace std;
int main() {
 double val[1010];
 while (~scanf("%lf", &val[0])) {
  char op;
  int ai = 0;
  double nex;
  while (~scanf("%c", &op) && op != '\n') {
   scanf("%lf", &nex);
   switch (op) {
   case '+':val[++ai] = nex; break;
   case '-':val[++ai] = -nex; break;
   case '*':val[ai] *= nex; break;
   case '/':val[ai] /= nex; break;
   }
  }
  double res=0;
  for (int i = 0; i <= ai; ++i)
       res += val[i];
  cout << res << endl;
 }
 return 0;
}