Hello Joanna

Link：https://vjudge.net/contest/174968#problem/C题目：The GeoSurvComp geologic survey company is responsible for detecting underground oil deposits. GeoSurvComp works with one large rectangular region of

Link：点击打开链接 Fox Ciel is playing a mobile puzzle game called "Two Dots". The basic levels are played on a board of size n × m cells, like this: Each cell contains a dot that has som

Link:https://vjudge.net/contest/174968#problem/E题目：Now give you an string which only contains 0, 1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,9.You are asked to add the sign ‘+’ or ’-’ between the characters. Just like giv

Link：https://vjudge.net/contest/174968#problem/H题目：Sometimes some mathematical results are hard to believe. One of the common problems is the birthday paradox. Suppose you are in a party where there ar

Link:http://acm.hdu.edu.cn/showproblem.php?pid=1312题目：There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, h