B 可以二分相遇的坐标:也可以二分时间,判断是否存在两个人的区间没有交. An easy way to intersect a number of segments [l1, r1], ..., [ln, rn] is to compute L = max li and R = min ri. If L ≤ R, then [L, R] is the intersection, otherwise, the intersection is empty. C dfs D 乱搞+思维 每个队名字非A…