Problems with strings MinGW

[coder_114]

I'm trying to convert an integer variable to a string using to_string function of string.h header file.
Here's the part of code:

string numToStr=to_string(num);

However, when I try to compile my program I get the following error:
[color=#FF0000]"error:to_string was not declared in this scope"[/color]

I'm using CodeBlocks as my IDE and my compiler is MinGW 4.8.1-4. Can anyone tell me why is this error showing up and how to fix this issue?

[leppyr64]

It only works C++11
stackoverflow.com/questions/1556 ... d-in-scope

SPOJ doesn't have C++11, so you'll need to do something different here. Some options are to create your own function or to use a stringstream. It's also entirely possible that there's a way that you don't need to do that at all.

Are you trying to solve a specific problem?

[coder_114]

It only works C++11
stackoverflow.com/questions/1556 ... d-in-scope

SPOJ doesn't have C++11, so you'll need to do something different here. Some options are to create your own function or to use a stringstream. It's also entirely possible that there's a way that you don't need to do that at all.

Are you trying to solve a specific problem?

Yes, I'm trying to solve PALIN1. To check if the number is palindrome, I'm trying to convert it to a string and then use the inbuilt function to_string of string.h file to reverse and check if it equals the original number. But it looks like I'll have to adopt an altogether different approach. Do you have any other clever tricks to achieve the same result?

[leppyr64]

Don't take the input as a number, take the input as a string.

And why are you solving PALIN1? It's a hidden problem, aka, not ready for use.

[coder_114]

Don't take the input as a number, take the input as a string.

And why are you solving PALIN1? It's a hidden problem, aka, not ready for use.

Sorry, its PALIN. And here's my modified code. However, the compiler is still throwing errors.

#include<iostream>
#include<vector>
#include<string.h>
using namespace std;
string palin(string num)
{
	string rev=strrev(num);
	while(strcmp(num,rev)!=0){
		num++;
	}
	return num;
}
int main()
{
	string t,out;
	vector<string> k;
	cin>>t;
	for(ui i=0;i<t;i++){
		cin>>k[i];
		out=palin(k[i]);
		cout<<out<<endl;
	}
	return 0;
}

[leppyr64]

What is the compiler error you are getting now?

[coder_114]

What is the compiler error you are getting now?

Here's it:

ideone.com/XV2l4z

[leppyr64]

"prog.cpp:10: error: 'strrev' was not declared in this scope"
strrev doesn't exist.

"prog.cpp:11: error: cannot convert 'std::string' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'"
char* and string are different. If you want to compare string just use ==.

"prog.cpp:12: error: no 'operator++(int)' declared for postfix '++', trying prefix operator instead
prog.cpp:12: error: no match for 'operator++' in '++num'"
You can't use ++ on a string.

"prog.cpp:22: error: no match for 'operator<' in 'i < t'"
You have t defined as a string and i as an unsigned integer. These do not have a valid comparison function for <.

[coder_114]

"prog.cpp:10: error: 'strrev' was not declared in this scope"
strrev doesn't exist.

"prog.cpp:11: error: cannot convert 'std::string' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'"
char* and string are different. If you want to compare string just use ==.

"prog.cpp:12: error: no 'operator++(int)' declared for postfix '++', trying prefix operator instead
prog.cpp:12: error: no match for 'operator++' in '++num'"
You can't use ++ on a string.

"prog.cpp:22: error: no match for 'operator<' in 'i < t'"
You have t defined as a string and i as an unsigned integer. These do not have a valid comparison function for <.

Here's my edited code:
ideone.com/03Dd8u

But this time I'm getting a runtime error.

[leppyr64]

10^1000000 does not fit in an unsigned integer.

[coder_114]

10^1000000 does not fit in an unsigned integer.

So what data type should I use?

[leppyr64]

An array of some sort would work.