题目链接：http://exam.upc.edu.cn/problem.php?id=5124题目：题目描述Flow Free is a puzzle that is played on a 2D grid of cells, with some cells marked as endpoints of certain colors and the rest of cells being b...
题目链接：http://exam.upc.edu.cn/problem.php?id=5121题目：题目描述Alice and Bob are in their class doing drills on multiplication and division. They quickly get bored and instead decide to play a game they inv...
题目链接：http://exam.upc.edu.cn/problem.php?id=5122题目：题目描述Mapping applications often represent the boundaries of countries, cities, etc. as polylines, which are connected sequences of line segments. Si...
题目链接：http://exam.upc.edu.cn/problem.php?id=5120题目：题目描述Open-pit mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow. Open-p...