[QGHG-it-dev-list] Zadatak 22 - Pachner-ov potez 3-u-2 (3-dim kompleks)

[Marko Vojinovic]

Implementirati f-ju koja ce da realizuje Pachner-ov potez 3-u-2 za kompleks dimenzije D=3:

    KSimplex* Pachner_move_3_to_2( KSimplex *simp, SimpComp *G );

    Input: 1-simpleks (1-5) nad kojim se vrsi potez, kompleks G.
    Output: 2-simpleks simp (2-3-4) koji se kreira potezom.

Pocetna struktura:

k=0: 1, 2, 3, 4, 5
k=1: (1-2), (1-3), (1-4), (2-3), (2-4), (3-4), (2-5), (3-5), (4-5), (1-5)
k=2: (1-2-3), (1-2-4), (1-3-4), (2-3-5), (2-4-5), (3-4-5), (1-2-5), (1-3-5), (1-4-5)
k=3: (1-2-3-5), (1-2-4-5), (1-3-4-5)

Finalna struktura:

k=0: 1, 2, 3, 4, 5
k=1: (1-2), (1-3), (1-4), (2-3), (2-4), (3-4), (2-5), (3-5), (4-5)
k=2: (1-2-3), (1-2-4), (1-3-4), (2-3-4), (2-3-5), (2-4-5), (3-4-5)
k=3: (1-2-3-4), (2-3-4-5)

Ovaj potez je inverz poteza 2-u-3. Neophodno je na pocetku proveriti da li input-edge (1-5) ima tacno tri tetraedra kao nad-susede, (1-2-3-5), (1-2-4-5), (1-3-4-5).

Algoritam se konstruise analogno prethodnim zadacima (ako nesto nije jasno, pitajte).

F-ja se testira bilo ispisivanjem tablica pomocu print_compact, ili uzastopnom primenom poteza 2-u-3 i nakon toga primenom inverznog poteza 3-u-2, koji treba da vrati kompleks u pocetno stanje.

:-)
Marko


Dr. Marko Vojinovic
Group for Gravitation, Particles and Fields
Institute of Physics
University of Belgrade
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home page: www.markovojinovic.com
e-mail:    vmarko at ipb.ac.rs