Problem 45230. Remove duplicated triangles

Input T is a triangulation (triplet list of indices -positive integers-, each index refering to a vertex number in a corresponding vertices list).
It sometimes happens a triangle may be duplicated several times. The goal of this problem is to remove all the duplicated triangles of T, and to keep only one.
For instance if :
T_in = [1 2 3;...
4 5 6;...
1 2 3;...
7 8 9;...
6 4 5;...
10 11 12;...
2 1 3;...
8 7 9;...
10 11 12]
then the output must be :
T_out = [1 2 3;...
4 5 6;...
7 8 9;...
10 11 12]
since rows [1 2 3], [6 4 5], [2 1 3], [8 7 9], and [10 11 12] are just duplicata. Indeed triangle [i2 i1 i3] is the same as triangle [i1 i2 i3] for example.
Hypothesis :
  • T is always a N x 3 integer matrix with N > 0 (non empty matrix)
  • Each row / triangle of T always contains three distinct integers
See also
Solve

Solution Stats

54.21% Correct | 45.79% Incorrect
Last Solution submitted on Jul 06, 2025

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers46

Suggested Problems

More from this Author42

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!