Complex sentence: The calculation of each of these elements (except those near boundaries) includes b × b multiplications and b × b--1 additions, so the time complexity is O ((a + b) 2 b 2).
Split into simpler sentences: The calculation of each of these elements (except those near boundaries) includes b × b multiplications and b × b--1 additions. So the time complexity is O ((a + b) 2 b 2).