摘要：旅行comf 给你一个无向图，N(N<=500)个顶点, M(M<=5000)条边，每条边有一个权值Vi(Vi<30000)。给你两个顶点S和T，求一条路径，使得路径上最大边和最小边的比值最小。如果S和T之间没有路径，输出”IMPOSSIBLE”，否则输出这个比值，如果需要，表示成一个既约分数。 备 阅读全文

摘要：Destroy Walls Long times ago, there are beautiful historic walls in the city. These walls divide the city into many parts of area. Since it was not co 阅读全文

摘要：Constructing Roads There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to e 阅读全文