haskell remainings

• 1-1
• 1-2
• 8-2: memoize
• 10-1: bfs
• 10-2(*): bfs
• 12-1: dp
• 12-2: dp
• 14-2: memoize
• 16-2(*): memoize
• 17-1: dp
• 17-2: dp
• 18-2: coor compress
• 19-2(*): 包除原理じゃだめっぽい。memoize?
• 20-1: stateful
• 20-2: stateful