Getting run time error working with vectors - c++

Question

So, I read the problem 4.5 from Accelerated C++, and interpreted it rather wrong. I wrote a program which is supposed to display counts of a word in string. However, I have probably done something very stupid, and very wrong. I can't figure it out.
Here's the code: http://ideone.com/87zA7E.
Stackoverflow says links to ideone.com must be accompanied by code. Instead of pasting the all of it, I will just paste the function which I think is most likely at fault:
vector<str_info> words(const vector<string>& s) {
vector<str_info> rex;
str_info record;
typedef vector<string>::size_type str_sz;
str_sz i = 0;
while (i != s.size()) {
record.str = s[i];
record.count = 0;
++i; //edit
for (str_sz j = 0; j != s.size(); ++j) {
if (compare(record, s[j]))
++record.count;
}
for (vector<str_info>::size_type k = 0; k != s.size(); ++k) {
if (!compare(record, rex[k].str))
rex.push_back(record);
}
}
return rex;
}

Answer 1

One problem is that you have this:
str_sz i = 0;
while (i != s.size()) {
but you never increment i, leading to an endless loop. Inside of that loop, you're pushing elements into vector rex. A vector cannot contain an infinite number of elements.

Answer 2

Also, you are trying to access:
rex[k].str
in
for (vector<str_info>::size_type k = 0; k != s.size(); ++k) {
if (!compare(record, rex[k].str)) // rex is empty in the beginning!!
rex.push_back(record);
}
But you do not know whether rex has k+1 elements in it.
EDIT: Change your code to:
while (i != s.size()) {
// read new string into a record (initial count should be one).
str_info record;
record.str = s[i];
record.count = 1;
// check if this string already exists in rex
bool found = false;
for (vector<str_info>::size_type k = 0; k < rex.size(); ++k) {
if ( record.str == rex[k].str ) {
rex[k].count++;
found = true;
break;
}
}
i++;
if ( found )
continue;
// if it is not found then push_back to rex
rex.push_back( record );
}