UVa 1586 - Molar mass

  怎么样提取字母中夹杂的数字，这种最大是两位数的还算简单。

#include
#include
char a[85];
double M(char x)
{
    if(x=='C')
        return (12.01);
    else if(x=='H')
        return (1.008);
    else if(x=='O')
        return (16.00);
    else if(x=='N')
        return (14.01);
}
int main()
{
    int T;
    int n,i;
    scanf("%d",&T);
    while(T--)
    {
        double sum=0;
        int i;
        memset(a,0,sizeof(a));
        scanf("%s",a);
        n=strlen(a);
        for(i=0; i'9'))
            {
                sum+=M(a[i]);
            }
            if((a[i+1]>='1')&&(a[i+1]<='9'))
            {
                if((a[i+2]>='1')&&(a[i+2]<='9'))
                {
                    sum+=M(a[i])*((a[i+1]-'0')*10+(a[i+2]-'0'));
                    i+=2;
                }
                else
                {
                    sum+=M(a[i])*(a[i+1]-'0');
                    i+=1;
                }
            }
        }
        printf("%.3lf\n",sum);
    }
    return 0;
}