Runtime error for Leetcode question: Two Sum - c++

Question

Error:
Line 1034: Char 9: runtime error: reference binding to null pointer of type 'int' (stl_vector.h)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /usr/bin/../lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/stl_vector.h:1043:9
My Code:
vector<int> twoSum(vector<int>& nums, int target) {
vector<int> sol;
int temp, i = 0, l = nums.size();
while(true && i < l)
{
temp = nums[i] - target;
int it = nums.end() - find(nums.begin(), nums.end(), temp);
if(it == 0)
{ i++;
continue;
}
sol[0] = i;
sol[1] = it;
break;
}
return sol;
}

Answer 1

The problem statement from Two Sum - LeetCode says:
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
You can return the answer in any order.
The bigger issue in the posted implementation is the repeated access out of bounds of sol, which is declared as an empty vector:
vector<int> sol;
Later, in loop, it's accessed via operator[] at indices 0 and 1, but those elements don't exist. So, to fix it, just declare a vector of two elements.
std::vector<int> sol(2);
Other minor issues (not really errors) are the followings:
int temp, i = 0, l = nums.size();
while ( true && i < l )
{ // ^^^^^^^ Why? It's pointless.
int it = nums.end() - find(nums.begin(), nums.end(), temp);
// ^^^^^^^^^^^^
// This traverses the vector every time from the beginning, which is a waste.
// Also, "you may not use the same element twice".
// Just start from the element after nums[i].
if(it == 0) // Consider to invert the logic: break when a pair is found
{
i++;
continue;
}
sol[0] = i; // Already addressed, but...
sol[1] = it;
// ^^ I lied, this IS another error.
// Do you remember how 'it' was calculated?
break;
}
To summarize, this is a possible solution
std::vector<int> twoSum(std::vector<int> const& nums, int target)
{ // We are not modifying it, so ^^^^^
std::vector<int> sol(2);
// IMHO, a std::pair would have been a better fir, here.
for (auto i{ nums.cbegin() }; i != nums.cend(); ++i)
{ // It's const... ^
auto const j = std::find(i + 1, nums.cend(), *i - target);
// Don't count twice ^^^^^
if( j != nums.cend() )
{ // ^^
sol[0] = std::distance(nums.cbegin(), i);
sol[1] = std::distance(nums.cbegin(), j);
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Count from the beginning.
break;
}
}
return sol;
}