/* junior304.d
2008 junior problem 3
Smile with similies
Ask for 2 numbers; the number of adjectives and nouns
After you get the numbers and nouns and adjectives, out all possible similies
August 12th, 2008 */

//Imports
import std.stdio;

/*****
*Main*
*****/
void main()
{
	int numberOfAdjectives;
	scanf( "%d", &numberOfAdjectives );
	int numberOfNouns;
	scanf( "%d", &numberOfNouns );

	char[][] adjectives; //array of strings to hold the adjectives
	adjectives.length = 6; //max number that user enters is 5, 6 to be safe
	char[][] nouns; //same as above, but for nouns
	nouns.length = 6; //same as adjectives reason

	//get adjectives first
	for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified # of adjectives
	{
		scanf( "%s", &adjectives[ i ] );
	}

	//now get the # of nouns specified
	for ( int i = 0; i < numberOfNouns; i++ )
	{
		scanf( "%s", &nouns[ i ] );
	}

	//print out all possible similies
	for ( int i = 0; i < numberOfAdjectives; i++ )
	{
		for ( int j = 0; j < numberOfNouns; j++ )
		{
			//for every adjective, place a noun after and turn it into a similie
			writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
		}
	}
}


I get an accessviolation when I enter the last 2 for loops; any reason why?

Input is:
3
2
Easy
Soft
Smart
pie
rock

error!

Michael P. wrote:
> /* junior304.d
> 2008 junior problem 3
> Smile with similies
> Ask for 2 numbers; the number of adjectives and nouns
> After you get the numbers and nouns and adjectives, out all possible similies
> August 12th, 2008 */
> 
> //Imports
> import std.stdio;
> 
> /*****
> *Main*
> *****/
> void main()
> {
> 	int numberOfAdjectives;
> 	scanf( "%d", &numberOfAdjectives );
> 	int numberOfNouns;
> 	scanf( "%d", &numberOfNouns );
> 	
> 	char[][] adjectives; //array of strings to hold the adjectives
> 	adjectives.length = 6; //max number that user enters is 5, 6 to be safe 	char[][] nouns; //same as above, but for nouns
> 	nouns.length = 6; //same as adjectives reason
> 	
> 	//get adjectives first
> 	for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified # of adjectives
> 	{
> 		scanf( "%s", &adjectives[ i ] );
> 	}
> 	
> 	//now get the # of nouns specified
> 	for ( int i = 0; i < numberOfNouns; i++ )
> 	{
> 		scanf( "%s", &nouns[ i ] );
> 	}
> 	
> 	//print out all possible similies
> 	for ( int i = 0; i < numberOfAdjectives; i++ )
> 	{
> 		for ( int j = 0; j < numberOfNouns; j++ )
> 		{
> 			//for every adjective, place a noun after and turn it into a similie
> 			writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
> 		}
> 	}
> }
> 
> 
> I get an accessviolation when I enter the last 2 for loops; any reason why?
> 
> Input is:
> 3
> 2
> Easy
> Soft
> Smart
> pie
> rock
> 
> error!

quick fix is to use printf
printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );

i think (not sure don't really use phobos that much) scanf doesn't return strings in a format writef likes...

I though theres a readf but cant find documentation on it...

Most likely, this is failing because you are using scanf.  Stop using it :) Use din.readf instead:

import std.cstream;

char[] str;
din.readf("%s", &str);

-Steve

"Michael P." <baseball.mjp@gmail.com> wrote in message news:g7vi50$29f0$1@digitalmars.com...
> /* junior304.d
> 2008 junior problem 3
> Smile with similies
> Ask for 2 numbers; the number of adjectives and nouns
> After you get the numbers and nouns and adjectives, out all possible
> similies
> August 12th, 2008 */
>
> //Imports
> import std.stdio;
>
> /*****
> *Main*
> *****/
> void main()
> {
> int numberOfAdjectives;
> scanf( "%d", &numberOfAdjectives );
> int numberOfNouns;
> scanf( "%d", &numberOfNouns );
>
> char[][] adjectives; //array of strings to hold the adjectives
> adjectives.length = 6; //max number that user enters is 5, 6 to be safe
> char[][] nouns; //same as above, but for nouns
> nouns.length = 6; //same as adjectives reason
>
> //get adjectives first
> for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified # of
> adjectives
> {
> scanf( "%s", &adjectives[ i ] );
> }
>
> //now get the # of nouns specified
> for ( int i = 0; i < numberOfNouns; i++ )
> {
> scanf( "%s", &nouns[ i ] );
> }
>
> //print out all possible similies
> for ( int i = 0; i < numberOfAdjectives; i++ )
> {
> for ( int j = 0; j < numberOfNouns; j++ )
> {
> //for every adjective, place a noun after and turn it into a similie
> writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
> }
> }
> }
>
>
> I get an accessviolation when I enter the last 2 for loops; any reason why?
>
> Input is:
> 3
> 2
> Easy
> Soft
> Smart
> pie
> rock
>
> error!

On Thu, 14 Aug 2008 01:23:05 +0400, Wyverex <wyverex.cypher@gmail.com> wrote:

> Michael P. wrote:
>> /* junior304.d
>> 2008 junior problem 3
>> Smile with similies
>> Ask for 2 numbers; the number of adjectives and nouns
>> After you get the numbers and nouns and adjectives, out all possible similies
>> August 12th, 2008 */
>>  //Imports
>> import std.stdio;
>>  /*****
>> *Main*
>> *****/
>> void main()
>> {
>> 	int numberOfAdjectives;
>> 	scanf( "%d", &numberOfAdjectives );
>> 	int numberOfNouns;
>> 	scanf( "%d", &numberOfNouns );
>> 	
>> 	char[][] adjectives; //array of strings to hold the adjectives
>> 	adjectives.length = 6; //max number that user enters is 5, 6 to be safe 	char[][] nouns; //same as above, but for nouns
>> 	nouns.length = 6; //same as adjectives reason
>> 	
>> 	//get adjectives first
>> 	for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified # of adjectives
>> 	{
>> 		scanf( "%s", &adjectives[ i ] );
>> 	}
>> 	
>> 	//now get the # of nouns specified
>> 	for ( int i = 0; i < numberOfNouns; i++ )
>> 	{
>> 		scanf( "%s", &nouns[ i ] );
>> 	}
>> 	
>> 	//print out all possible similies
>> 	for ( int i = 0; i < numberOfAdjectives; i++ )
>> 	{
>> 		for ( int j = 0; j < numberOfNouns; j++ )
>> 		{
>> 			//for every adjective, place a noun after and turn it into a similie
>> 			writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
>> 		}
>> 	}
>> }
>>   I get an accessviolation when I enter the last 2 for loops; any reason why?
>>  Input is:
>> 3
>> 2
>> Easy
>> Soft
>> Smart
>> pie
>> rock
>>  error!
>
Your code is seriously broken!

The following line is wrong, for example:
> scanf( "%s", &nouns[ i ] );

What are you doing here? Are you out of your mind? You are passing a pointer to a char[]* to a function that accept a char*. Your array will be overwritten with whatever you will type. It is wrong, wrong, wrong!

I think that you don't understand something. First of all, what is a char[]? It is a struct that consists of a array size and a pointer:

struct CharArray {
   size_t size;
   char* ptr;
}

typeof(nounts[i]) is a char[], typeof(&nouns[i]) is char[]*. You pass this pointer to a function that accepts a pointer to a preallocated buffer for a string to be written to.

A quick fix would be to:
1) allocate a buffer:
nouns[i] = new char[64];
2) pass a pointer to the preallocated buffer:
scanf("%s", nouns[i].ptr);

A good fix would be to use readf instead. I didn't use it, but this should be sufficient:
readf("%s", &nouns[i]);


> quick fix is to use printf
> printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );
>
> i think (not sure don't really use phobos that much) scanf doesn't return strings in a format writef likes...
>
> I though theres a readf but cant find documentation on it...

Test before posting, please!

Koroskin Denis wrote:

> 
>> quick fix is to use printf
>> printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );
>>
>> i think (not sure don't really use phobos that much) scanf doesn't return strings in a format writef likes...
>>
>> I though theres a readf but cant find documentation on it...
> 
> Test before posting, please!



Worked on my machine!!  Though I am using tangobos....

Koroskin Denis Wrote:

> On Thu, 14 Aug 2008 01:23:05 +0400, Wyverex <wyverex.cypher@gmail.com> wrote:
> 
> > Michael P. wrote:
> >> /* junior304.d
> >> 2008 junior problem 3
> >> Smile with similies
> >> Ask for 2 numbers; the number of adjectives and nouns
> >> After you get the numbers and nouns and adjectives, out all possible
> >> similies
> >> August 12th, 2008 */
> >>  //Imports
> >> import std.stdio;
> >>  /*****
> >> *Main*
> >> *****/
> >> void main()
> >> {
> >> 	int numberOfAdjectives;
> >> 	scanf( "%d", &numberOfAdjectives );
> >> 	int numberOfNouns;
> >> 	scanf( "%d", &numberOfNouns );
> >> 
> >> 	char[][] adjectives; //array of strings to hold the adjectives
> >> 	adjectives.length = 6; //max number that user enters is 5, 6 to be
> >> safe 	char[][] nouns; //same as above, but for nouns
> >> 	nouns.length = 6; //same as adjectives reason
> >> 
> >> 	//get adjectives first
> >> 	for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified #
> >> of adjectives
> >> 	{
> >> 		scanf( "%s", &adjectives[ i ] );
> >> 	}
> >> 
> >> 	//now get the # of nouns specified
> >> 	for ( int i = 0; i < numberOfNouns; i++ )
> >> 	{
> >> 		scanf( "%s", &nouns[ i ] );
> >> 	}
> >> 
> >> 	//print out all possible similies
> >> 	for ( int i = 0; i < numberOfAdjectives; i++ )
> >> 	{
> >> 		for ( int j = 0; j < numberOfNouns; j++ )
> >> 		{
> >> 			//for every adjective, place a noun after and turn it into a similie
> >> 			writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
> >> 		}
> >> 	}
> >> }
> >>   I get an accessviolation when I enter the last 2 for loops; any
> >> reason why?
> >>  Input is:
> >> 3
> >> 2
> >> Easy
> >> Soft
> >> Smart
> >> pie
> >> rock
> >>  error!
> >
> Your code is seriously broken!
> 
> The following line is wrong, for example:
> > scanf( "%s", &nouns[ i ] );
> 
> What are you doing here? Are you out of your mind? You are passing a pointer to a char[]* to a function that accept a char*. Your array will be overwritten with whatever you will type. It is wrong, wrong, wrong!
> 
> I think that you don't understand something. First of all, what is a char[]? It is a struct that consists of a array size and a pointer:
> 
> struct CharArray {
>     size_t size;
>     char* ptr;
> }
> 
> typeof(nounts[i]) is a char[], typeof(&nouns[i]) is char[]*. You pass this pointer to a function that accepts a pointer to a preallocated buffer for a string to be written to.
> 
> A quick fix would be to:
> 1) allocate a buffer:
> nouns[i] = new char[64];
> 2) pass a pointer to the preallocated buffer:
> scanf("%s", nouns[i].ptr);
> 
> A good fix would be to use readf instead. I didn't use it, but this should
> be sufficient:
> readf("%s", &nouns[i]);
> 
> 
> > quick fix is to use printf
> > printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );
> >
> > i think (not sure don't really use phobos that much) scanf doesn't return strings in a format writef likes...
> >
> > I though theres a readf but cant find documentation on it...
> 
> Test before posting, please!


Sorry I made you angry...

I changed all the scanfs to din.readfs and everything worked okay... does that solve my passing a pointer to a string to function that accepts a pointer to a char?
I guess I should check the documentation for some stuff like that.

On Thu, 14 Aug 2008 04:21:05 +0400, Michael P. <baseball.mjp@gmail.com> wrote:

> Koroskin Denis Wrote:
>
>> On Thu, 14 Aug 2008 01:23:05 +0400, Wyverex <wyverex.cypher@gmail.com>
>> wrote:
>>
>> > Michael P. wrote:
>> >> /* junior304.d
>> >> 2008 junior problem 3
>> >> Smile with similies
>> >> Ask for 2 numbers; the number of adjectives and nouns
>> >> After you get the numbers and nouns and adjectives, out all possible
>> >> similies
>> >> August 12th, 2008 */
>> >>  //Imports
>> >> import std.stdio;
>> >>  /*****
>> >> *Main*
>> >> *****/
>> >> void main()
>> >> {
>> >> 	int numberOfAdjectives;
>> >> 	scanf( "%d", &numberOfAdjectives );
>> >> 	int numberOfNouns;
>> >> 	scanf( "%d", &numberOfNouns );
>> >> 	
>> >> 	char[][] adjectives; //array of strings to hold the adjectives
>> >> 	adjectives.length = 6; //max number that user enters is 5, 6 to be
>> >> safe 	char[][] nouns; //same as above, but for nouns
>> >> 	nouns.length = 6; //same as adjectives reason
>> >> 	
>> >> 	//get adjectives first
>> >> 	for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified #
>> >> of adjectives
>> >> 	{
>> >> 		scanf( "%s", &adjectives[ i ] );
>> >> 	}
>> >> 	
>> >> 	//now get the # of nouns specified
>> >> 	for ( int i = 0; i < numberOfNouns; i++ )
>> >> 	{
>> >> 		scanf( "%s", &nouns[ i ] );
>> >> 	}
>> >> 	
>> >> 	//print out all possible similies
>> >> 	for ( int i = 0; i < numberOfAdjectives; i++ )
>> >> 	{
>> >> 		for ( int j = 0; j < numberOfNouns; j++ )
>> >> 		{
>> >> 			//for every adjective, place a noun after and turn it into a  
>> similie
>> >> 			writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
>> >> 		}
>> >> 	}
>> >> }
>> >>   I get an accessviolation when I enter the last 2 for loops; any
>> >> reason why?
>> >>  Input is:
>> >> 3
>> >> 2
>> >> Easy
>> >> Soft
>> >> Smart
>> >> pie
>> >> rock
>> >>  error!
>> >
>> Your code is seriously broken!
>>
>> The following line is wrong, for example:
>> > scanf( "%s", &nouns[ i ] );
>>
>> What are you doing here? Are you out of your mind? You are passing a
>> pointer to a char[]* to a function that accept a char*. Your array will be
>> overwritten with whatever you will type. It is wrong, wrong, wrong!
>>
>> I think that you don't understand something. First of all, what is a
>> char[]? It is a struct that consists of a array size and a pointer:
>>
>> struct CharArray {
>>     size_t size;
>>     char* ptr;
>> }
>>
>> typeof(nounts[i]) is a char[], typeof(&nouns[i]) is char[]*. You pass this
>> pointer to a function that accepts a pointer to a preallocated buffer for
>> a string to be written to.
>>
>> A quick fix would be to:
>> 1) allocate a buffer:
>> nouns[i] = new char[64];
>> 2) pass a pointer to the preallocated buffer:
>> scanf("%s", nouns[i].ptr);
>>
>> A good fix would be to use readf instead. I didn't use it, but this should
>> be sufficient:
>> readf("%s", &nouns[i]);
>>
>>
>> > quick fix is to use printf
>> > printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );
>> >
>> > i think (not sure don't really use phobos that much) scanf doesn't
>> > return strings in a format writef likes...
>> >
>> > I though theres a readf but cant find documentation on it...
>>
>> Test before posting, please!
>
>
> Sorry I made you angry...
>

No, you didn't. It just proves that C functions are unsafe and hard to use.

> I changed all the scanfs to din.readfs and everything worked okay... does that solve my passing a pointer to a string to function that accepts a pointer to a char?

Yes, I think.

> I guess I should check the documentation for some stuff like that.

Well, you should understand what are you doing when using C library. It is unsafe and very error-prone.
In fact, you were doing fine, just used wrong function. Compare the following:

char[] buffer; scanf("%s", &buffer); vs char[] buffer; readf("%s", &buffer);

They are almost the same, but D version (readf) is an order of magnitude smarter and safer because of type-safe variadic functions.

> > Sorry I made you angry...
> >
> 
> No, you didn't. It just proves that C functions are unsafe and hard to use.
> 
> > I changed all the scanfs to din.readfs and everything worked okay... does that solve my passing a pointer to a string to function that accepts a pointer to a char?
> 
> Yes, I think.
> 
> > I guess I should check the documentation for some stuff like that.
> 
> Well, you should understand what are you doing when using C library. It is
> unsafe and very error-prone.
> In fact, you were doing fine, just used wrong function. Compare the
> following:
> 
> char[] buffer; scanf("%s", &buffer); vs char[] buffer; readf("%s", &buffer);
> 
> They are almost the same, but D version (readf) is an order of magnitude smarter and safer because of type-safe variadic functions.


Okay, thanks, I'll be using readf from now on. :D
-Michael P.

"Michael P." wrote
> Koroskin Denis Wrote:
>
>> On Thu, 14 Aug 2008 01:23:05 +0400, Wyverex
>> wrote:
>>
>> > Michael P. wrote:
>> >> /* junior304.d
>> >> 2008 junior problem 3
>> >> Smile with similies
>> >> Ask for 2 numbers; the number of adjectives and nouns
>> >> After you get the numbers and nouns and adjectives, out all possible
>> >> similies
>> >> August 12th, 2008 */
>> >>  //Imports
>> >> import std.stdio;
>> >>  /*****
>> >> *Main*
>> >> *****/
>> >> void main()
>> >> {
>> >> int numberOfAdjectives;
>> >> scanf( "%d", &numberOfAdjectives );
>> >> int numberOfNouns;
>> >> scanf( "%d", &numberOfNouns );
>> >>
>> >> char[][] adjectives; //array of strings to hold the adjectives
>> >> adjectives.length = 6; //max number that user enters is 5, 6 to be
>> >> safe char[][] nouns; //same as above, but for nouns
>> >> nouns.length = 6; //same as adjectives reason
>> >>
>> >> //get adjectives first
>> >> for ( int i = 0; i < numberOfAdjectives; i++ ) //get the specified #
>> >> of adjectives
>> >> {
>> >> scanf( "%s", &adjectives[ i ] );
>> >> }
>> >>
>> >> //now get the # of nouns specified
>> >> for ( int i = 0; i < numberOfNouns; i++ )
>> >> {
>> >> scanf( "%s", &nouns[ i ] );
>> >> }
>> >>
>> >> //print out all possible similies
>> >> for ( int i = 0; i < numberOfAdjectives; i++ )
>> >> {
>> >> for ( int j = 0; j < numberOfNouns; j++ )
>> >> {
>> >> //for every adjective, place a noun after and turn it into a similie
>> >> writefln( "%s as %s", adjectives[ i ], nouns[ j ] );
>> >> }
>> >> }
>> >> }
>> >>   I get an accessviolation when I enter the last 2 for loops; any
>> >> reason why?
>> >>  Input is:
>> >> 3
>> >> 2
>> >> Easy
>> >> Soft
>> >> Smart
>> >> pie
>> >> rock
>> >>  error!
>> >
>> Your code is seriously broken!
>>
>> The following line is wrong, for example:
>> > scanf( "%s", &nouns[ i ] );
>>
>> What are you doing here? Are you out of your mind? You are passing a
>> pointer to a char[]* to a function that accept a char*. Your array will
>> be
>> overwritten with whatever you will type. It is wrong, wrong, wrong!
>>
>> I think that you don't understand something. First of all, what is a char[]? It is a struct that consists of a array size and a pointer:
>>
>> struct CharArray {
>>     size_t size;
>>     char* ptr;
>> }
>>
>> typeof(nounts[i]) is a char[], typeof(&nouns[i]) is char[]*. You pass
>> this
>> pointer to a function that accepts a pointer to a preallocated buffer for
>> a string to be written to.
>>
>> A quick fix would be to:
>> 1) allocate a buffer:
>> nouns[i] = new char[64];
>> 2) pass a pointer to the preallocated buffer:
>> scanf("%s", nouns[i].ptr);
>>
>> A good fix would be to use readf instead. I didn't use it, but this
>> should
>> be sufficient:
>> readf("%s", &nouns[i]);
>>
>>
>> > quick fix is to use printf
>> > printf( "%s as %s", &adjectives[ i ], &nouns[ j ] );
>> >
>> > i think (not sure don't really use phobos that much) scanf doesn't return strings in a format writef likes...
>> >
>> > I though theres a readf but cant find documentation on it...
>>
>> Test before posting, please!
>
> I changed all the scanfs to din.readfs and everything worked okay... does that solve my passing a pointer to a string to function that accepts a pointer to a char?

Yes.  both scanf and din.readf are variadic functions (meaning, they take a variable number and type of arguments).  However, readf is D variadic, meaning that along with the addresses of all the variables you want to read, it also gets a TypeInfo telling the function which type each argument is. So it can check and make sure you are passing the right type.  In fact, I think %s is a catch all which means for readf to use the TypeInfo to tell how to scan the arguments in.

The scanf function is C variadic, and so does not have this ability.  So when you are passing a pointer and saying 'scan in a char*', it has to take your word for it that you are actually passing a char ** (even though you were passing a char[] *)

Note that char[] is not the same as char*.  The former is a struct with a char* and a length in it.  The fact that it worked in your code at all is a miracle :)

Glad you got it working!

-Steve

On Wed, 13 Aug 2008 17:35:42 -0400, "Steven Schveighoffer" <schveiguy@yahoo.com> wrote:

>
>Most likely, this is failing because you are using scanf.  Stop using it :) Use din.readf instead:
>
>import std.cstream;
>
>char[] str;
>din.readf("%s", &str);
>

The code above causes an Access Violaion in D2. The following works.

import std.stdio   : writeln;
import std.cstream : din;

int main() {
	char[] str;
	din.readf(&str);
	writeln(str);
	return 0;
}


Gide