Submission #9029626

---

Source Code Expand

#include <cstdio>
#include <algorithm>
#include <vector>

const int MN = 100005;

int N;
std::vector<int> G[MN];
int dep[MN], faz[MN], o[MN], cnt[MN], tp;

void DFS(int u, int fz) {
	dep[u] = dep[faz[u] = fz] + 1;
	for (auto v : G[u]) if (v != fz) DFS(v, u);
}

int main() {
	scanf("%d", &N);
	for (int i = 1, x, y; i < N; ++i)
		scanf("%d%d", &x, &y),
		G[x].push_back(y),
		G[y].push_back(x);
	DFS(1, 0);
	int u = 0, v = 0;
	for (int i = 1; i <= N; ++i) if (dep[u] < dep[i]) u = i;
	DFS(u, 0);
	for (int i = 1; i <= N; ++i) if (dep[v] < dep[i]) v = i;
	for (int x = v; x != u; x = faz[x]) o[x] = ++tp;
	o[u] = ++tp;
	for (int i = 1; i <= N; ++i) if (!o[i]) {
		if (G[i].size() == 1) ++cnt[o[G[i][0]]];
		else return puts("-1"), 0;
	}
	int rev = 0;
	for (int i = 1, j = tp; i < j; ++i, --j)
		if (cnt[i] != cnt[j]) { rev = cnt[i] > cnt[j]; break; }
	if (rev) std::reverse(cnt + 1, cnt + tp + 1);
	int now = 1;
	for (int i = 1; i <= tp; ++i) {
		for (int j = 1; j <= cnt[i]; ++j) printf("%d ", now + j);
		printf("%d ", now), now += cnt[i] + 1;
	}
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:17:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
                 ^
./Main.cpp:21:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   G[y].push_back(x);
                    ^

Judge Result