I've got several times WA 10 and in the forum I couldn't find any test for this test, and finally I found where was the mistake.

Try this:
(*  WTF?!!
*
)

answer is yes

Test: ((**)*)
My answer is YES, but if we delete comment (**) it will remain only (*) and it must be arithmetic expr, but it's not cuz arithmetic expressions can't start with (*, so the right answer is NO, am I wrong?

char s[16384] ;
unsigned n = 0;

 //  AC  0.001s with this code.
    for(int c = std::getc(stdin); c != EOF; c = std::getc(stdin))
       s[n++] = c;

// and AC 0.015s with   n = fread(s,1,sizeof(s)-1,stdin);  code.

// I'm wonder that  the std::getc faster than fread!!

[deleted]

P.S. Don't EVER forget to initialize your variables.

Edited by author 30.01.2015 01:18

Edited by author 30.01.2015 01:19

I use "string ch" AC,but " char ch[maxn]" WA4,I don't know why .....

Note*: if you have WA1 just skip all #10 and #13 symbols from input data!

((*Answer is YES*))
(((*Answer is YES*)))
(**) YES
 (* NO
(*) NO
(*(*) YES
(11(*)) NO
(*(**)*) NO
((**)*)(**)*)  NO!
((**)*)  YES

()()
(())
((())) YES

(1+1
)  YES

Can anybody tell what the problem ?

Edited by author 30.12.2012 19:51

I think my program is correct. Who can tell me why I got wa?

#include<cstdio>
#include<cstdlib>
#include<cstring>
char a[100005],b[100000];
char cs[]="=+-*/0123456789)(";
bool pd(char ch){
    for(int i=0;i<17;i++)
       if(ch==cs[i]) return 1;
    return 0;
}

int main(){
    while(gets(b)){
       strcat(a,b);
    }
    int len=strlen(a);
    int ha=0,k=0;
    for(int i=0;i<len;i++){
         if(ha){
            if(a[i]=='*' && a[i+1]==')')
                ha=0;
         }else{
            if(a[i]=='*' && a[i-1]=='(')
                ha=1;
            else{
                if(k>0 && (!pd(a[i]))){ printf("NO"); return 0; }
                if(a[i]=='(') k++;
                if(a[i]==')') k--;
                if(k<0) { printf("NO"); return 0;}
            }
         }
    }
    if(ha || k!=0) { printf("NO"); return 0; }
    else printf("YES");
    system("pause");
    return 0;
}

If you have WA1 just skip all #10 and #13 symbols from input data!

You may not still be in a comment when you finish reading all input.

Hey, everybody! I'd like to ask for a test data of this problem similar to test #8. I've read through the discussions and passed all the test data given in earlier topics but still got stuck at #8. Any help will be appreciated!!


Edited by author 07.04.2012 14:05

Is there any link where I can access\download the input test vectors for problem "1027. D++ Again" ?

-Hari

use state machine with char-by-char reading. We know last char and last state, so we can find next state. Brackets should be counting during reading. If we have '(', so we plus 1, ')' - minus 1. If brackets < 0 and state is some of arifmetic state - it's error.

Try this short test:
(*(**)
Answer is YES

This test was suggested by Nazar (Lviv NU) (http://acm.timus.ru/author.aspx?id=24760) and tested by Gleb Grenkin (http://acm.timus.ru/author.aspx?id=37338).
This test helped me a lot. Thanks to above men.

New tricky test was added, and all AC submissions were rejudged. 96 authors lost AC.

why test#26 ...    what mean?

I use this and get AC:

char str[30010];
int strsize = 0;
while (fgets(str + strsize, 20000, stdin)) strsize = strlen(str) - 1;
++strsize;

do not save newlines!
make if to skip them
for example:
cin >> noskipws;
while(cin >> ch) {
    if (ch != '\n')
        s[n++] = ch
}

This is my code:
#include <stdio.h>
#include <string.h>
#define ulong unsigned long
void main()
{
#ifndef ONLINE_JUDGE
    freopen("in.txt","rt",stdin);
    freopen("out.txt","wt",stdout);
#endif
    bool comment=0,arithmetical=0;
    long brakets=0;
    char syms[10001];
    ulong i=0;
    while(fgets(syms+i,10000,stdin))
    {
        i=strlen(syms)-1;
    }
    for(i=0;i<strlen(syms);++i)
    {
        if(comment)
        {
            for(;i<strlen(syms);++i)
                if(syms[i]=='*'&&syms[i+1]==')')
                {
                    ++i;
                    comment=0;
                    break;
                }
            continue;
        }
        if(arithmetical)
        {
            for(;i<strlen(syms);++i)
            {
                if(!((syms[i]>=0x28&&syms[i]<=0x2B)||(syms[i]>=0x30&&syms[i]<=0x39)||syms[i]=='-'||syms[i]=='/'||syms[i]=='='))
                {
                    printf("NO");
                    return;
                }
                if(syms[i]=='(')
                {
                    if(syms[i+1]=='*')
                    {
                        ++i;
                        comment=1;
                        break;
                    }
                    ++brakets;
                }
                if(syms[i]==')')
                {
                    --brakets;
                    if(!brakets)
                    {
                        arithmetical=0;
                        break;
                    }
                }
            }
            continue;
        }
        for(;i<strlen(syms);++i)
        {
            if(syms[i]=='(')
            {
                if(syms[i+1]=='*')
                {
                    ++i;
                    comment=1;
                    break;
                }
                ++brakets;
                arithmetical=1;
                break;
            }
            if(syms[i]==')')
            {
                printf("NO");
                return;
            }
        }
    }
    if(comment||arithmetical)
    {
        printf("NO");
        return;
    }
    printf("YES");
}
why wa 26?

This is my code:
#include <stdio.h>
#define ulong unsigned long
void main()
{
#ifndef ONLINE_JUDGE
    freopen("in.txt","rt",stdin);
    freopen("out.txt","wt",stdout);
#endif
    bool comment=0,arithmetical=0;
    long brakets=0;
    char syms[10001];
    ulong i;
    while(!feof(stdin))
    {
        gets(syms);
        i=0;
        while(syms[i])
        {
            if(comment)
            {
                while(syms[i])
                {
                    if(syms[i]=='*')
                    {
                        ++i;
                        if(syms[i]==')')
                        {
                            ++i;
                            comment=0;
                            break;
                        }
                    }
                    ++i;
                }
            }
            if(arithmetical)
            {
                while(syms[i])
                {
                    if(!((syms[i]>=0x28&&syms[i]<=0x2B)||(syms[i]>=0x30&&syms[i]<=0x39)||syms[i]=='-'||syms[i]=='/'||syms[i]=='\n'||syms[i]=='='))
                    {
                        printf("NO");
                        return;
                    }
                    if(syms[i]=='(')
                    {
                        ++i;
                        if(syms[i]=='*')
                        {
                            ++i;
                            comment=1;
                            break;
                        }
                        ++brakets;
                        continue;
                    }
                    if(syms[i]==')')
                    {
                        ++i;
                        --brakets;
                        if(!brakets)
                        {
                            arithmetical=0;
                            break;
                        }
                    }
                    ++i;
                }
                continue;
            }
            while(syms[i])
            {
                if(syms[i]=='(')
                {
                    ++i;
                    if(syms[i]=='*')
                    {
                        ++i;
                        comment=1;
                        break;
                    }
                    arithmetical=1;
                    ++brakets;
                    break;
                }
                if(syms[i]==')')
                {
                    printf("NO");
                    return;
                }
                ++i;
            }
        }
    }
    if(arithmetical||comment)
    {
        printf("NO");
        return;
    }
    printf("YES");
}
WHY WA1?!