palindrome and mirrored string

Question

i'm writing a code that read lines of string and check if it's mirrored, palindrome or mirrored palindrome the problem is that it's always displaying wrong value's for inputs except the last one

Sample Input:

NOTAPALINDROME 
ISAPALINILAPASI 
2A3MEAS 
ATOYOTA

Code:

  #include<iostream>
  #include<string>
  #include<vector>
  using namespace std;

bool is_palindrome(const string &s)
{
    for(int i=0,j=s.length()-1;i!=j;i++,j--)
    {
        if(s[i]!=s[j])
            return false;
    }
    return true;
}
char get_mirror(const char &c)
{
    switch(c)
    {

    case 'A':return c;
    case 'E':return '3';
    case 'H':return c;
    case 'I':return c;
    case 'J':return 'L';
    case'L':return 'J';
    case'M':return c;
    case 'O':return c;
    case 'S':return '2';
    case 'T':return c;
    case'U':return c;
    case'W':return c;
    case'X':return c;
    case'Y':return c;
    case'Z':return '5';
    case'1':return c;
    case'2':return 'S';
    case'3':return 'E';
    case'5':return 'Z';
    case'8':return c;
    default: return'-1'; 

    }
}
 bool is_mirrored(const string &s)
 {
     for(int i=0,j=s.length()-1;i!=j;i++,j--)
     {
         if(get_mirror(s[i])!=s[j])
         {
             return false;

         }
     }
     return true;

 }

int main()
{
    vector<string>cases;
    vector<string>::iterator pt;
    string temp;
    while(getline(cin,temp))
    {
        cases.push_back(temp);

    }
    for(pt=cases.begin();pt!=cases.end();pt++)
    {
        cout<<*pt<<"    "<<is_palindrome(*pt)<<"   "<<is_mirrored(*pt)<<endl;
    }

    system("pause");
    return 0;
}

Output if many strings:

NOTAPALINDROME
ISAPALINILAPASI
2A3MEAS
ATOYOTA
^Z
NOTAPALINDROME     0   0
ISAPALINILAPASI     0   0
2A3MEAS     0   0
ATOYOTA    1   1
Press any key to continue . . .

Output if one string:

2A3MEAS
^Z
2A3MEAS    0   1
Press any key to continue . . .

Could you show us what the output is for the sample input you gave? — Scott Mermelstein, Mar 12 '13 at 15:21
This shouldn't even compile `'-1'` is not a valid character. — Bart Friederichs, Mar 12 '13 at 15:22
What is this getMirror function?? so many letters (all letters of the last input word) return their own value and not mirror value? and so many letters are missing — idoo, Mar 12 '13 at 15:25
Visually, there's no reason for it to give the wrong results, which makes me suspect an invisible culprit. I'm going to blame whitespace. Dukeling's right about getting to know your debugger. Set a breakpoint, look at each string, and I bet you'll see some trailing whitespace in all but the last input. — Scott Mermelstein, Mar 12 '13 at 15:34
@AkiSuihkonen, I would say `i <= j` in the mirrored case so that `5` is not a mirrored palindrome and `A` is. — unkulunkulu, Mar 12 '13 at 15:38
@idoo some letters are mirrored by it self The missing letters are letters with no mirror value — Nader, Mar 12 '13 at 16:05

score 2 · Accepted Answer · edited May 23 '17 at 12:07

2

Your input seems to have additional whitespace that's wrecking your string checks. Evidence of this is that your ouput for the many strings show 5 spaces instead of the 4 it should, except in the final line. Either clean your input manually, or trim your input string in your program. (See, e.g. What's the best way to trim std::string?.)

edited May 23 '17 at 12:07

Community

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answered Mar 12 '13 at 15:38

Scott Mermelstein

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I do agree with Aki Suihkonen and unkulunkulu's comments about tweaking your loop, though - your code as it is will fail on even length strings, though that's not the issue you're bringing up. – Scott Mermelstein Mar 12 '13 at 15:42
1

As an aside, it's very helpful when debugging string issues in any language to have delimiters that help you "see" whitespace. E.g., if your output line was `cout<<'\''<<*pt<<'\''" "< – Scott Mermelstein Mar 12 '13 at 15:48
1

yes,it's a white space problem and i fixed the loop issue thanks a lot ^_^ – Nader Mar 12 '13 at 15:52

palindrome and mirrored string

1 Answers1