总时间限制: 1000ms 内存限制: 65536kB 描述 Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point locating in the sea side. And
描述 The famous ACM (Advanced Computer Maker) Company has rented a floor of a building whose shape is in the following figure. The floor has 200 rooms each on the north side and south side along the c
踩方格 查看提交统计提示提问 总时间限制: 1000ms 内存限制: 65536kB 描述 有一个方格矩阵,矩阵边界在无穷远处。我们做如下假设: a. 每走一步时,只能从当前方格移动一格,走到某个相邻的方格上; b. 走过的格子立即塌陷无法再走第二次; c. 只能向北、东、西三个方向走; 请问:如果允许在方格矩阵上走n步,共有多少种不同的方案。2种走法只要