Thread: oops ! code crashing.. :(

yup.. Im making a new exercise from a book im reading to learn c++
but what i did cant be good cause evry time i run it the program bugs.. (not computer tho..)

here it is:

Code:

void program()
{
	int i;
	char juju[20];
	typedef pair<char,char> twin;
	twin bob;
	vector<twin> here;
	here.push_back(bob);
	cout<<"Enter a string of maximum 15 characters."<<endl;
	cin>>juju;
	for (i=0;i<10;i++)
	{
			here[i]=make_pair(juju[i],juju[i+1]);
	}
	for (i=0;i<19;i++)
	{
		cout <<i<<" " <<here[i].first<< here[i].second <<"\n";
	}
}

what I've been asked to do (in book) is:

Write a function that counts the number of occurences of a pair of letter in a string and another that does the same in zero-terminated array of char (a C-style string). For example, the pair "AB" appears twice in "XABAACBAXABB".

So i used vector so it will grow to fit the lenght of th string(right?) and pair holds 2 char which I will compare (eventually) with each other so this way I will know there is a matching pair..

so what is wrong?
vector doesnt grow all by itself maybe?

thx in advance..
Luigi

ofc it doesnt compile i didnt want to spam so i just posted the part im having problem with..
just add

Code:

#include <iostream>
using namespace std;

void program();

int main()
{
program();
return 0;
}

and thats it..
but i tought it was obvious??

as for the push_back thing.. is there a way i could make it so it check if needs to grow if yes push_back somethin if not stay as is?

caus I'd like to make it so that the vector actually only the size needed for every string I enter each time wich will be different size each time.. (see my point?)

anyway thx again..

Luigi

no way to control the exact capacity of vectors in STL. That is up to the implementors. You could implement your own version, but that would defeat the purpose of standardization wouldn't it.

Code:

typedef pair<char,char> twin;
twin bob;
vector<twin> here;
here.push_back(bob);//think twice here. bob has no value. do you really want him in your group?

cout<<"Enter a string of maximum 15 characters."<<endl;
cin>>juju;

for (i=0;i<strlen(juju) - 1;i++)//don't overread your data!
{
     here.push_back(make_pair(juju[i], juju[i+1]));

}
for (s=0;s< i;s++)//likewise, don't overread your data
{
  cout <<s<<" " <<here[s].first<< ','<< here[s].second <<"\n";
}

thx alot elad..
That really helped me out..

with ur help found the bug:

here[i]=make_pair(juju[i],juju[i+1]);


that is what was making console crash.
and using strlen(juju) is what i was searching for..


really thx again..