QuickSort for vector<string> - c++

Question

I'm new to recursion and get kind of confused by it this is my first time coding Quick Sort for a string I keep getting an error. Does anyone know where I messed up?
#include <iostream>
#include <string>
#include <fstream>
#include <vector>
using namespace std;
void SwapValue(string &a, string &b)
{
string t = a;
a = b;
b = t;
}
void quicksort(vector<string> &list, int first, int end)
{
int l = first;
int r = end;
int pivot = ((first + end) / 2);
while (l <= r)
{
while (list[l] <= (list[pivot]))
++l;
while (list[r] >= (list[pivot]))
--r;
if (l <= r)
{
swap(list[l], list[r]);
++l;
--r;
}
}
if (first <= r)
quicksort(list, first, r);
if (end >= l)
quicksort(list, l, end);
}
void print(vector <string> const &a)
{
cout << "[ ";
for(int i=0; i < a.size(); i++)
{
cout << a[i] << ' ';
}
cout << ']';
}
int main()
{
vector<string> test = {"Bob", "Andrew", "Joe"};
quicksort(test, 0, test.size()-1);
print(test);
return 0;
}
I thought about getting the ASCII values of the first char within the string but I would have to use a nested forloop to retrieve the character and wouldn't that make QuickSort slower?

Answer 1

This statement:
while (list[l] <= (pivot))
How does that even compile? Comparing a string to an integer?
I suspect you mean:
while (list[l] <= list[pivot])
Similar treatment is also needed for the while (list[r] >= (pivot)) statement. And I don't think you want to use >= on the right side.
while (i <= r)
That won't compile either since i is not defined. I suspect you meant l, not 'i'.