UVA - 1586 Molar Mass

UVA - 1586 Molar Mass

#include<cstdio>
#include<cstring>
#include<cctype>
double molar[4]={12.01,1.008,16.00,14.01};
int aaa[20];
int main(){
aaa[2]=0;aaa[7]=1;aaa[14]=2;aaa[13]=3;
int cc;
scanf("%d",&cc);
char temp[10000];
while(cc--)
{
memset(temp,0,sizeof(temp));
scanf("%s",temp);
char a;
int b=0;
double sum=0;
for(int i=0;i<strlen(temp);i++){
if(isalpha(temp[i]))
{
a=temp[i];
if(isalpha(temp[i+1])||temp[i+1]=='\0')
b=1;
}
else if(isdigit(temp[i]))
{
while(isdigit(temp[i]))
{
b+=temp[i]-'0';
b*=10;
i++;
}
b/=10;
i--;
}
if(b&&b==1)
{sum+=molar[aaa[a-'A']];
b=0;
}
else
{
sum+=molar[aaa[a-'A']]*b;
b=0;
}
}
printf("%.3lf\n",sum);
}

return 0;

}