UVA-1586 Molar Mass - ACM/ICPC Seoul 2007

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int main()
{
int T;cin>>T;
while(T--){
double sum=0.0,m=1.0;int k=1;
char s[100];cin>>s;int num=strlen(s);
for(int i=num-1;i>=0;i--){
if(s[i]>='0'&&s[i]<='9'){
if(k==1) m=0;
m+=k*(s[i]-'0');
k*=10;
}//if
else {
k=1;double c;
if(s[i]=='C') c=12.010;
else if(s[i]=='H') c=1.008;
else if(s[i]=='O') c=16.000;
else c=14.010;
sum+=m*c;
m=1.0;
}
}//for
printf("%.3lf\n",sum);//格式，lf不是llf
}//while
return 0;
}