=== open3d-0001: ValidatePoseGraphConnectivity — O(V²×E) std::find on component vector inside BFS×edge scan ===
N=100   k=100  : defective=0.085ms  fixed=0.003ms  speedup=24.9x
N=500   k=500  : defective=2.131ms  fixed=0.020ms  speedup=104.6x
N=1000  k=1000 : defective=8.689ms  fixed=0.046ms  speedup=190.8x
N=2000  k=2000 : defective=38.009ms  fixed=0.097ms  speedup=390.6x

=== open3d-0002: RandomSampler::operator() — O(S²) std::find on samples vector inside rejection-sampling loop ===
N=100   k=100  : defective=0.084ms  fixed=0.003ms  speedup=24.6x
N=500   k=500  : defective=2.174ms  fixed=0.021ms  speedup=105.6x
N=1000  k=1000 : defective=8.740ms  fixed=0.064ms  speedup=136.8x
N=2000  k=2000 : defective=38.376ms  fixed=0.097ms  speedup=397.4x

