/* -*- coding: utf-8 -*- * * 2301.cc: No.2301 Namorientation - yukicoder */ #include #include #include #include using namespace std; /* constant */ const int MAX_N = 200000; /* typedef */ typedef pair pii; typedef vector vpii; struct UFT { vector links, ranks, sizes; UFT() {} void init(int n) { links.resize(n); for (int i = 0; i < n; i++) links[i] = i; ranks.assign(n, 1); sizes.assign(n, 1); } int root(int i) { int i0 = i; while (links[i0] != i0) i0 = links[i0]; return (links[i] = i0); } int rank(int i) { return ranks[root(i)]; } int size(int i) { return sizes[root(i)]; } bool same(int i, int j) { return root(i) == root(j); } int merge(int i0, int i1) { int r0 = root(i0), r1 = root(i1), mr; if (r0 == r1) return r0; if (ranks[r0] == ranks[r1]) { links[r1] = r0; sizes[r0] += sizes[r1]; ranks[r0]++; mr = r0; } else if (ranks[r0] > ranks[r1]) { links[r1] = r0; sizes[r0] += sizes[r1]; mr = r0; } else { links[r0] = r1; sizes[r1] += sizes[r0]; mr = r1; } return mr; } }; /* global variables */ int as[MAX_N], bs[MAX_N]; vpii nbrs[MAX_N]; UFT uft; int ps[MAX_N], cis[MAX_N]; bool es[MAX_N]; /* subroutines */ /* main */ int main() { int n; scanf("%d", &n); for (int i = 0; i < n; i++) { scanf("%d%d", as + i, bs + i); as[i]--, bs[i]--; nbrs[as[i]].push_back({bs[i], i}); nbrs[bs[i]].push_back({as[i], i}); } uft.init(n); int re = -1; for (int i = 0; i < n; i++) { if (! uft.same(as[i], bs[i])) uft.merge(as[i], bs[i]); else re = i; } int rt = as[re]; //printf("re=%d, rt=%d\n", re, rt); ps[rt] = -1; es[re] = true; for (int u = rt; u >= 0;) { vpii &nbru = nbrs[u]; int up = ps[u]; if (cis[u] < nbru.size()) { auto [v, ei] = nbru[cis[u]++]; if (v != up && ei != re) { ps[v] = u; es[ei] = (as[ei] == v); u = v; } } else u = up; } for (int i = 0; i < n; i++) { if (es[i]) puts("->"); else puts("<-"); } return 0; }