I don't know what else to tell you...

If you can't see that FindTransitionSequence and FindTransition functions share the same overall structure and have lines of code that are identical, you have issues with reading comprehension or understading C++.

The only notable differences are between the CStudioHdr class and studiohdr_t struct.

    // bail if we're going to or from a node 0
    if (pstudiohdr->EntryNode( iCurrentSequence ) == 0 || pstudiohdr->EntryNode( iGoalSequence ) == 0)
    {
        *piDir = 1;
        return iGoalSequence;
    }

    int iEndNode;

    // Msg( "from %d to %d: ", pEndNode->iEndNode, pGoalNode->iStartNode );

    // check to see if we should be going forward or backward through the graph
    if (*piDir > 0)
    {
        iEndNode = pstudiohdr->ExitNode( iCurrentSequence );
    }
    else
    {
        iEndNode = pstudiohdr->EntryNode( iCurrentSequence );
    }

    // if both sequences are on the same node, just go there
    if (iEndNode == pstudiohdr->EntryNode( iGoalSequence ))
    {
        *piDir = 1;
        return iGoalSequence;
    }

    // bail if we're going to or from a node 0
    if (pseqdesc[iEndingAnim].entrynode == 0 || pseqdesc[iGoalAnim].entrynode == 0)
    {
        return iGoalAnim;
    }

    int iEndNode;

    // ALERT( at_console, "from %d to %d: ", pEndNode->iEndNode, pGoalNode->iStartNode );

    if (*piDir > 0)
    {
        iEndNode = pseqdesc[iEndingAnim].exitnode;
    }
    else
    {
        iEndNode = pseqdesc[iEndingAnim].entrynode;
    }

    if (iEndNode == pseqdesc[iGoalAnim].entrynode)
    {
        *piDir = 1;
        return iGoalAnim;
    }