Copying char * pointer to char array variable

Question

I've created a Word scribble solver and it basically computes the permutations of a given word and compares it with the available dictionary. But the problem is I've to copy a char pointer into an array char variable to compare them and I don't know how to do it. Below is my code snippet:

#include<fstream>
#include<string>
#include<ctype>

using namespace std;

void swap(char *x, char *y)
{
    char temp;
    temp = *x;
    *x = *y;
    *y = temp;
}

void permute(char *a, int l, int r)
{
    char word[25], word1[25];
    fstream flame;
    if(l == r)
    {
        word1 = *a;      /* <— Error! */
        flame.open("dic.sly", ios::in);
        while(!flame.eof())
        {
            flame << word;
            tolower(word[0]);
            if(strcmp(word, word1) == 0)
                cout << word;
        }
        flame.close();
    }
    else
    {
        for(int i = l; i <= r; i++)
        {
            swap((a + l), (a + i));
            permute(a, l + 1, r);
            swap((a + l), (a + i));
        }
    }
}

void main()
{
    char str[] = "lonea";
    int n = strlen(str);
    permute(str, 0, n - 1);
}

I've quoted where I'm getting the error. Please, correct if there are any mistakes.

It would be greatly appreciated if you would fix your indentation to make your code easier to read. Some examples of good indentation can be found here: en.wikipedia.org/wiki/Indentation_style#Styles — C_Elegans
– C_Elegans, Commented Feb 6, 2018 at 3:38
#include<string> -- This is not the correct header for the C-style strings. The correct header is <cstring>. The <string> header is for std::string, which you make no use of in your program whatsoever. — PaulMcKenzie
– PaulMcKenzie, Commented Feb 6, 2018 at 3:53
You really ought to avoid using namespace std - it is a bad habit to get into, and can silently change the meaning of your program when you're not expecting it. Get used to using the namespace prefix (std is intentionally very short), or importing just the names you need into the smallest reasonable scope. — Toby Speight
– Toby Speight, Commented Feb 6, 2018 at 14:48

Bo Persson · Accepted Answer · 2018-02-06 03:45:18Z

1

To copy one C-style string to another you have to use strcpy(word1, a);. Only if you use std::string (recommended!) can you assign using =.

You also have a mistake in flame<<word; where you try to write to the input file. To read words you need flame >> word;.

It probably would have been easier to use std::swap instead of implementing your own.

Another bit is tolower(word[0]); which doesn't modify the parameter but returns the result. You ought to save that.

answered Feb 6, 2018 at 3:45

Bo Persson

92.9k31 gold badges153 silver badges211 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

SlayerDiAngelo Over a year ago

This code was written for turbo c++ compiler(academic reason), sorry for incorrect header files

Collectives™ on Stack Overflow

Copying char * pointer to char array variable

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related