C++ Crossword Word Generator Fixed

I’m building a small puzzle game and need a C++ routine that turns a pre-defined list of words into a classic crossword-style grid.

The goal is to do a puzzles generator based on the following input :
- grid size (in practice will be 7*9, 7*10, 7*11
- dictionnary of best words (D1)
- dictionnary of excellent words (D2)
- dictionnary of good words (D3)
- dictionnary of average words (D4, usually contains single letters)

All dictionnaries are basic .txt files with one word per line, D1 will contain around 1000 words, D2 maybe 5000, D3 1000 and D4 26.

All words read from top to bottom and left to right.

Constraints such as : we want at least 20% of words from D1, 30% from D2.

The code should be fast with the given grids, the fastest the best, but we can tolerate max 5-10 seconds per grid.
Doesnt matter the method (smart brute force or constraint programming), as long as it generates valid puzzles within the given time.

When generating a grid we need to keep track of the provenance of each word (which dictionary it was taken from).
I have source code and it needs some fix.