https://www.bnuoj.com/v3/contest_show.php?cid=9154#problem/K
【Accepted】
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<string> 5 #include<cmath> 6 #include<algorithm> 7 #include<queue> 8 #include<stack> 9 #include<map> 10 using namespace std; 11 const int maxn=2e2+3; 12 const double eps=1e-6; 13 char str[maxn]; 14 15 int main() 16 { 17 double n; 18 char ch; 19 char op[3]; 20 while(~scanf("%lf%c",&n,&ch)) 21 { 22 if(n==0.0&&ch==' ') 23 { 24 break; 25 } 26 stack<double> num; 27 num.push(n); 28 while(scanf("%s%lf",op,&n)) 29 { 30 if(op[0]=='+') 31 { 32 num.push(n); 33 } 34 else if(op[0]=='-') 35 { 36 num.push(-n); 37 } 38 else if(op[0]=='*') 39 { 40 double tmp=num.top()*n; 41 num.pop(); 42 num.push(tmp); 43 } 44 else if(op[0]=='/') 45 { 46 double tmp=num.top()/n; 47 num.pop(); 48 num.push(tmp); 49 } 50 ch=getchar(); 51 if(ch==' ') 52 break; 53 } 54 double ans=0.0; 55 while(!num.empty()) 56 { 57 ans+=num.top(); 58 num.pop(); 59 } 60 printf("%.2f ",ans); 61 } 62 return 0; 63 }