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I don't know why this got CE.
Posted: Fri Apr 07, 2006 2:03 pm
by shines
This go well on my machine, but I got CE. Why?
Posted: Fri Apr 07, 2006 5:57 pm
by Cho
It can be compiled succesfully by MinGW. But I got a strange compilation error from g++ in unix:
t.cpp:7: parse error before `+'
I then modify it and the following code can be compiled without error:
Code: Select all
#include <iostream>
#include <string>
#include <cstdio>
using namespace std;
/*
bool isupper(char x){
return (x >= 'A' && x <= 'Z')? true: false;
}
*/
int value(char x){
if(isupper(x))
return x-38;
return x-96;
}
bool isprime(int n){
if(n == 0 || n == 1) return true;
for(int i=2; i<n/2; i++){
if(n % i == 0)
return false;
}
return true;
}
int main(int argc, char **argv){
string word;
int sum;
while(getline(cin, word)){
if(word.empty()) break;
sum = 0;
for(int i=0; i<word.size(); i++){
sum += value(word[i]);
}
if(isprime(sum))
cout << "It is a prime word." << endl;
else
cout << "It is not a prime word." << endl;
}
return 0;
}
Looks like upper() is defined even you don't include ctype.h.
Posted: Fri Apr 07, 2006 6:35 pm
by shines
I compiled with g++ 4.0 in linux. it's no problem.
but acm show this error message:
04482233_24.c:6: parse error before `)'
04482233_24.c:6: parse error before `&'
I used isupper() that I defined at another problem. It got AC. why this time it cause matter?
Posted: Fri Apr 07, 2006 9:18 pm
by mf
There's an isupper() defined in <ctype.h> and <cctype>.
Probably <iostream> caused that file to be included, and it conflicted with your version of isupper(). And you know, sometimes isupper is defined as a macro. (i.e. #define isupper(c) ...)
Re: I don't know why this got CE.
Posted: Fri Apr 07, 2006 9:35 pm
by Krzysztof Duleba
shines wrote:Code: Select all
#include <iostream>
bool isprime(int n){
if(n == 0 || n == 1) return true;
for(int i=2; i<n/2; i++){
if(n % i == 0)
return false;
}
return true;
}
BTW: are you sure you want isprime() to work this way? According to it 0 and 1 are prime, so is 4. I don't think you'll get AC with that.
Posted: Sat Apr 08, 2006 12:26 am
by little joey
Yes, isupper is defined as a macro, at least in the compiler the judge uses. You can avoid compile error by first undef-ing it:
Code: Select all
#include <iostream>
#include <string>
#include <cstdio>
using namespace std;
#undef isupper
bool isupper(char x){
return (x >= 'A' && x <= 'Z')? true: false;
}
int value(char x){
if(isupper(x))
return x-38;
return x-96;
}
... etc.
and then it will compile fine.
Re: I don't know why this got CE.
Posted: Sat Apr 08, 2006 5:33 am
by Cho
Krzysztof Duleba wrote:shines wrote:Code: Select all
#include <iostream>
bool isprime(int n){
if(n == 0 || n == 1) return true;
for(int i=2; i<n/2; i++){
if(n % i == 0)
return false;
}
return true;
}
BTW: are you sure you want isprime() to work this way? According to it 0 and 1 are prime, so is 4. I don't think you'll get AC with that.
Btw, it's too slow, although it may pass for that particular problem.
By adding 3 characters and deleting 2 characters, it will be improved from O(n) to O(sqrt(n)).
Re: I don't know why this got CE.
Posted: Sat Apr 08, 2006 6:16 am
by shines
Krzysztof Duleba wrote:shines wrote:Code: Select all
#include <iostream>
bool isprime(int n){
if(n == 0 || n == 1) return true;
for(int i=2; i<n/2; i++){
if(n % i == 0)
return false;
}
return true;
}
BTW: are you sure you want isprime() to work this way? According to it 0 and 1 are prime, so is 4. I don't think you'll get AC with that.
you are right. I make a mistake there. So I got WA after solve CE problem.
Now I fix it and got AC. Thanks.