check this tests for "Not a floating point number"
-
1
-.
1
-.e0
1
-.1e
1
#123
1
--123
1
-1.e6
1

And last one (when I fixed this, I got Accepted):
-e20
1

Of course this is not an exhaustive list of possible bugs. Good luck, guys!

You have to be very careful with scanf. It is wrong to write something like "scanf("%d\n", &n);" It took me a month to find this bug.

You can use BigDecimal constructor for checking the validity of number. After some preprocessing to the realnumber String. Good luck.

It is not clear if empty lines can be used in the input.
Is the next example possible?
<empty line>
5
#

It is clear that we can't have leading spaces in case correct real number. But is it possible to have spaces after correct number till the end of the string?
Example:
1.2e-3SSS
5
#

It states in the problem that the input stops by 2 lines. First one is "#\n", but what is in the second line of input termination? Is there any number N or it can be just CR?

try this:

-7293874219874982174982174987321E-18446744073709551616
10
#

expected to be
0.0000000000

Hi everyone!

I had WA#12 for quite a long time, even after I had tried all the tests listed here. I finally got AC after I checked the input for space characters (isspace). After that I hardcoded a check for ' ', '\n', '\r', '\t', '\v', '\f', '\a', '\b', (and removed the isspace) and it gave me WA. In the C standart isspace gives true only for space, newline (\n), carrige return (\r), horizontal tab (\t), vertical tab (\v), form feed (\f) AND others depending on the locale... I cannot understand what kind of symbols they have put in this test case because my program doesn't allow any whitespace at all (I handle each character one by one, and I look for perfect match for isdigit, '+', '-', '\0', 'e', 'E', so I just cant miss a space character) I suggest review of this test case and removing any fancy characters found in it.

If someone wants to see my solution email me iskren [dot] chernev [at] gmail [dot] com

var x:real;s,s1:string; c,n:integer;
begin

repeat
readln(s);
val(s,x,c);
if s='#' then halt;

readln(s1);
if c=0 then begin val(s1,n,c);writeln(x:0:n) end else
  writeln('Not a floating point number');

until s1='#';

end.

Edited by author 22.03.2011 16:49

Edited by author 22.03.2011 16:49

1e100000000000000
2
> 0.00

1) the exponent may be very large (absolute value). e.g. -100000000000000000000000000000000000.
2) the exponent may pretend to be very large, but actually not. e.g. 000000000000000000000000000000000010
3) 12.e1 is not a valid floating point number, because the dot cannot be the last character of the integral part according to the grammar mentioned.

good luck

why WA?

Edited by author 08.04.2010 14:57

I've check all the data here..but i still get WA#12..

#include <iostream>
#include <cstring>
#include <string>
#define inf 214748364
using namespace std;
struct tmono
{
    int n[9000];
    int w,nega,xs;
};
char s[1000];
int xs,len,con,e;
tmono num;
string res;
inline bool isnum(char ch)
{
    return '0'<=ch&&ch<='9';
}
inline bool getnum(int st,int en,tmono &e)
{
    memset(e.n,0,sizeof(e.n));
    e.w=0;e.xs=0;e.nega=0;
    if(s[st]=='-')    e.nega=1,++st;
    else
    if(s[st]=='+')    e.nega=0,++st;
    /*
    while(s[st]=='+'||s[st]=='-')
    {
        if(s[st]=='-')
            e.nega=!e.nega;
        ++st;
    }
    */
    for(int i=en;i>=st;i--)
    if(s[i]=='.')
    {
        e.xs=en-i;
        for(int j=i;j<en;j++)
            s[j]=s[j+1];
        --en;
        break;
    }
    for(int i=st;i<=en;i++)
    if(!isnum(s[i]))
        return 0;
    e.w=0;
    for(int i=en;i>=st;i--)
        e.n[++e.w]=s[i]-'0';
    return 1;
}
inline bool work()
{
    res="";
    cin>>xs;
    int tempxs=xs;
    scanf("\n");
    if(s[0]=='.')
    {
        for(int i=len-1;i>=0;i--)
            s[i+1]=s[i];
        s[0]='0';
        len++;
    }
    if(!isnum(s[0])&&s[0]!='-'&&s[0]!='+')
        return 0;
    con=0;
    for(int i=0;i<len;i++)
    {
    if(s[i]=='e'||s[i]=='E')
    {
        if(con!=0)
            return 0;
        con=i;
    }
    if(s[i]!='e'&&s[i]!='E'&&s[i]!='-'&&s[i]!='+'
        &&s[i]!='.'&&!isnum(s[i]))
            return 0;
    if(s[i]=='.'&&!isnum(s[i+1]))
        return 0;
    }
    e=0;
    bool enega=0;
    if(con!=0)
    {
        e=-inf;
        int j=con;
        con++;
        if(s[con]=='+'||s[con]=='-')
        {
            if(s[con]=='-')    enega=!enega;
            con++;
        }
        /*
        while(s[con]=='-'||s[con]=='+')
        {
            if(s[con]=='-')    enega=!enega;
            ++con;
        }*/
        for(int i=con;i<len;i++)
        {
            if(!isnum(s[i]))
                return 0;
            if(e==-inf)
                e=0;
            e=e*10+s[i]-'0';
            if(e>500)
                break;
        }
        if(e==-inf)
            return 0;
        if(enega)
            e*=-1;
        len=j;
    }
    --len;
    if(!getnum(0,len,num))
        return 0;
    num.xs-=e;
    while(num.n[num.w]==0&&num.w>0)
        --num.w;
    bool isxs=0;
    if(num.xs<=0)
    {
        for(int i=num.w;i>=1;i--)
            res+=num.n[i]+'0';
        while(num.xs<0)
        {
            res+="0";
            num.xs++;
        }
    }else
    {
        int j=max(num.w,num.xs);
        if(num.xs>num.w)
        {
            num.w=num.xs;
            num.xs=0;
            res+="0.";
            isxs=1;
        }
        for(int i=j;i>=1;i--)
        {
            if(i==num.xs)
                isxs=1;
            if(isxs&&xs==0)
                break;
            if(i==num.xs)
                res+=".";
            if(isxs)--xs;
            res+=num.n[i]+'0';
        }
    }
    while(xs>0)
    {
        if(!isxs)
            res+=".",isxs=1;
        res+="0",--xs;
    }
    while(res[0]=='0')
        res.erase(0,1);
    if(res.length()==0)
        res.insert(0,"0");
    if(res[0]=='.')
        res.insert(0,"0");
    for(int i=0;i<res.length();i++)
    if(res[i]=='.')
        if(res.length()-i<tempxs)
        {
            tempxs-=res.length()-i;
            while(tempxs--)
                res.insert(res.length()-1,"0");
        }else
            res.erase(i+tempxs,res.length()-i-tempxs-1);
    if(res[res.length()-1]=='.')
        res.erase(res.length()-1,1);

    if(num.nega)
    for(int i=0;i<res.length();i++)
    if('1'<=res[i]&&res[i]<='9')
    {
        res.insert(0,"-");
        break;
    }
    for(int i=1;i<res.length();i++)
    if(res[i]=='.'&&!isnum(res[i-1]))
    {
        res.insert(i,"0");
        break;
    }
    if(res[res.length()-1]=='.')    res.erase(res.length()-1,1);

    res+="\n";
    return 1;
}
inline void reads()
{
        memset(s,0,sizeof(s));
        gets(s);
        len=strlen(s);
        while(len>=1&&isspace(s[len-1]))
            s[len]=0,--len;
        while(isspace(s[0]))
        {
            for(int j=0;j<len-1;j++)
                s[j]=s[j+1];
            s[len]=0;len--;
        }
}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("input.in","r",stdin);
    freopen("output.out","w",stdout);
    #endif
    reads();
    while(!(strlen(s)==1&&s[0]=='#'))
    {
        if(!work())
            printf("Not a floating point number\n");
            else
            cout<<res;
        reads();
    }
    return 0;
}

NOT FLOATING FOR
1)1E2.1

2)2E2+1

3)2E2-1

4)E

5)-+3

6)3EE

-----------------------------------------
1)
1E1 1
10.0

1E+1 1
10.0

0E10 1
0.0

0 1
0.0

000.1 1
0.1

0.1E1 0
1

I got Crash on Test #12...I don't know why.
My e-mail: xiaomengxian@gmail.com
Please send sth to my e-mail if it is not convienent to say here. Thanx.

I tried with Scanner and BufferedReader, but have no luck :(
Help????

Well ... My solution gives the right answer for the sample test case , for all forum test cases, and for test cases [1,11]. But, Wrong Answer #12 :S. What's the trick.. ?!
Every test case I test on my solution works fine for me.
Does anyone know some more tricky test cases???

why

10
0.0
-0.0
1100000000000000000000000000000.0000000000
-0.0
24680976.32135864232426891300
Not a floating point number
Not a floating point number

is incorrect output for the sample (test#1)?

Edited by author 24.10.2008 23:22