摘要：题意 "题目链接" 问从$0$出发能否回到$0$且边权为负 Sol 先用某B姓算法找到负环，再判一下负环上的点能否到$0$ cpp include define chmax(x, y) (x = (x y ? x : y)) define chmin(x, y) (x = (x define MP 阅读全文