Problem 45262. Remove duplicated vertices

First input V_in is a vertices list (X Y Z coordinates) which may contain duplicata (identical rows).
Second input T_in is the corresponding triangulation , in which each integer represents the row index of the vertex in the list V_in.
First output V_out -the easiest to compute- is the list of vertices without duplicata.
Second output T_out is a bit more tricky to compute : once you get rid of duplicated vertices, you of course have to update their corresponding indices in the triangulation array. The resulting table is T_out which admit no duplicated triangle.
NB : triangle orientations in T_out doesn't matter : [i1 i2 i3] is the same as [i3 i2 i1] for instance
Example on a regular octahedron included in the unit sphere :
V_in = [0 0 1;...
sqrt(2) sqrt(2) 0;...
-sqrt(2) sqrt(2) 0;...
0 0 1;...
-sqrt(2) -sqrt(2) 0;...
sqrt(2) sqrt(2) 0;...
sqrt(2) -sqrt(2) 0;...
0 0 -1];
T_in = [1, 2, 3;...
1, 3, 5;...
4, 5, 7;...
2, 4, 7;...
2, 3, 8;...
3, 5, 8;...
5, 7, 8;...
2, 7, 8];
V_out = [0 0 1;...
sqrt(2) sqrt(2) 0;...
-sqrt(2) sqrt(2) 0;...
-sqrt(2) -sqrt(2) 0;...
sqrt(2) -sqrt(2) 0;...
0 0 -1];
T_out = [1, 2, 3;...
1, 2, 5;...
1, 3, 4;...
1, 4, 5;...
2, 3, 6;...
2, 5, 6;...
3, 4, 6;...
4, 5, 6];
See also
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Solution Stats

47.25% Correct | 52.75% Incorrect
Last Solution submitted on Nov 16, 2025

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