「codeforces - 1486F」Pairs of Paths
link。还算萌,但是代码有些难写……你首先会想要int n, m, fa[20][300100], pa[300100], dep[300100], cnt[900100];
int ldf[...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.