Manhattan Distances
Awesome Atek
F - Distinct Numbers
F - Fork in the Road
E - Non-triangular Triplets
C - Swaps
F - Laminate
Codeforces Round 251 (Div. 2) D. Devu and his Brother
Codeforces Round 253 (Div. 1) A. Borya and Hanabi
Codeforces Round 257 (Div. 1) A. Jzzhu and Chocolate