PAT (Advanced Level) 1108. Finding Average (20)

简单模拟。

#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#include<algorithm>
using namespace std;

char s[];
int n;
int num,num2,pos;

bool f()
{
    int p=;
    for(int i=;s[i];i++)
    {
        if(s[i]>=''&&s[i]<='') continue;
        else if(i==&&s[i]=='-') continue;
        else if(s[i]=='.') {p++; continue;}
        else return ;
    }

    if(p>) return ;

    pos=strlen(s);
    for(int i=;s[i];i++) if(s[i]=='.') pos=i;

    int hh=strlen(s)-pos-;
    if(hh>) return ;

    num=;
    for(int i=;i<pos;i++)
    {
        if(s[i]>=''&&s[i]<='')
            num=num*+s[i]-'';
        if(num>) return ;
    }
    if(num>) return ;

    num2=;
    for(int i=pos+;s[i];i++)
        num2=num2*+s[i]-'';

    double a=1.0*num+num2/(pow(10.0,strlen(s)-pos-));
    if(a>1000.0) return ;

    return ;
}

int main()
{
    scanf("%d",&n);
    double sum=;
    int  geshu=;
    for(int i=;i<=n;i++)
    {
        scanf("%s",s);
        if(f()==)
            printf("ERROR: %s is not a legal number\n",s);
        else
        {
            double a=;
            a=1.0*num+num2/(pow(10.0,strlen(s)-pos-));
            if(s[]=='-') a=-a;
            sum=sum+a;
            geshu++;
        }
    }
    if(geshu==)
        printf("The average of 1 number is %.2lf\n",sum);
    else if(geshu==)
        printf("The average of 0 numbers is Undefined\n");
    else
        printf("The average of %d numbers is %.2lf\n",geshu,sum/geshu);
    return ;
}