struct method partly changes the values of it's member array cpp - c++

Question

Some information about the overall project:
I have to find if specific nodes remain connected if i start removing the lowest width edges from a graph. I have a struct solve, which has a member array called connected. In a method of this struct , FindConnections I go over some of the edges, from the Kth till the last and see which nodes are connected. The way I keep track of the connected nodes is to have an array that for each node points to the lowest id node it is connected, with the lowest pointing to itself
for example
if nodes 2 5 6 12 are directly connected
connected[2] =connected[5] =connected[6] =connected[12] = 2
so now if 12 and 23 are connected (and 12 is the lowest connection of 23)
connected [23] = 12 and connected[connected[23]] = 2 so i can reach 2 from 23 with recursion
My problem is that after finishing modifying the connected array inside FindConnections, some of the changes are preserved while other not
Here is the code:
void FindConnections(int index)
{
for (int temp, i = index; i < NumberOfPortals; i++)
{
temp = min(first[i], second[i]); // the nodes which edge i connects
connected[first[i]] = temp;
connected[second[i]] = temp;
}
}
which is called by
void seeAllConnections() // this function is for visualization it will not be included
{
for (int i = NumberOfPortals - 1; i >= 0; --i)
{
printf("Only using %d Portals:\n", NumberOfPortals - i);
FindConnections(i);
seeconnected(); // prints connected array
for (int i = 0; i < NumberOfUniverses; i++) //resets connected array
{
connected[i] = i;
}
}
}
In the two first iterations of the for loop in seeAllConnections, everything is good, the edges that are examined are
first second width(irrelevant for now)
6 7 255
26 2 111
11 7 36
in the beginning everyone is connected with himself
in the first one we get the output
(I am placing ** around the values that are changed and !! around the one that was supposed to change but didn't , just so you can see it better, the program prints just the numbers)
Only using 1 Portals:
connected are:
0 1 2 3 4 5 6 7 8 9 10 *7* 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
and we can see that connected[11] = 7 just like we wanted to
in the second one
Only using 2 Portals:
connected are:
0 1 2 3 4 5 6 7 8 9 10 *7* 12 13 14 15 16 17 18 19 20 21 22 23 24 25 *2* 27 28 29
connected[11] =7 just like before
connected[26] = 2 just like we wanted
in the third one
Only using 3 Portals:
connected are:
0 1 2 3 4 5 6 !7! 8 9 10 *7* 12 13 14 15 16 17 18 19 20 21 22 23 24 25 *2* 27 28 29
connected [7] = 7 , not 6
moreover, when i use gdb, inside the FindConnections loop, connected[7] = 6 like we wanted
(gdb) print first[i]
$10 = 6
(gdb) print second[i]
$11 = 7
(gdb) print connected[first[i]]
$12 = 6
(gdb) print connected[second[i]]
$13 = 6
but when it exits the function and returns to seeAllConnected
connected[7] = 7
What Am I doing wrong? how can the first two changes be preserved form the same function in the same struct in the same loop, while the second one isn't?
Also after every time I call FindConnections I reset the array to it's original values, so the changes couldn't have been preserved from before
Thank you in advance

Answer 1

I found out what was wrong, as it was a reverse iteration connected[7] got overwritten.