oj.uz

Submission #317072

# Submission time Handle Problem Language Result Execution time Memory
317072 2020-10-29T02:34:47 Z Kevin_Zhang_TW Balanced Tree (info1cup18_balancedtree) C++17
10 / 100
 610 ms 30328 KB 
#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] : ", args)
void kout() { cerr << endl; }
template<class T, class ...U>
void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
void debug(auto L, auto R) { while (L != R) cerr << *L << " \n"[next(L) == R], ++L; }
#else
#define debug(...) 0
#define DE(...) 0
#endif
const int MAX_N = 500010, inf = 1e9;
int n, c[MAX_N];
vector<int> edge[MAX_N];
void clear() {
	for (int i = 1; edge[i].size() ; ++i)
		edge[i].clear();
}
int dis[MAX_N], sz[MAX_N];
bool ban[MAX_N];
int dfs_sz(int x, int lst = -1) {
	sz[x] = 1;
	for (int u : edge[x]) if (u != lst && !ban[u])
		sz[x] += dfs_sz(u, x);
	return sz[x];
}
int dfs_cen(int x, int allsz, int lst = -1) {
	for (int u : edge[x]) if (u != lst && !ban[u])
		if (sz[u] * 2 > allsz)
			return dfs_cen(u, allsz, x);
	return x;
}

void chmin(int &v, int val) { v = min(v, val); }
int min_dep[2];
void dfs_update(int x, int lst = -1) {
	static int d;
	if (ban[x]) return;
	++d;
	chmin(dis[x], min_dep[c[x]] + d);
	chmin(min_dep[c[x]], d);
	for (int u : edge[x]) if (u != lst)
		dfs_update(u, x);
	--d;
}
void dfs_solve(int side) {
	if (ban[side]) return;
	int cen = dfs_cen(side, dfs_sz(side));

	min_dep[0] = min_dep[1] = inf;
	
	min_dep[ c[cen] ] = 0;
	for (int u : edge[cen]) 
		dfs_update(u);

	min_dep[0] = min_dep[1] = inf;

	reverse(AI(edge[cen]));

	for (int u : edge[cen])
		dfs_update(u);

	chmin(dis[cen], min_dep[c[cen]]);

	ban[cen] = true;
	for (int u : edge[cen])
		dfs_solve(u);
}
	
void cal_init() {
	for (int i = 1;i <= n;++i) {
		dis[i] = inf;
		ban[i] = false;
	}
}
int cal() {
	dfs_solve(1);
	return *max_element(dis+1, dis+n+1);
}
int bfs(int s) {
	queue<pair<int,int>> q;
	vector<bool> vis(n+1);
	q.emplace(s, 0);
	vis[s] = true;
	while (q.size()) {
		auto [x, len] = q.front(); q.pop();
		if (x != s && c[x] == c[s])
			return len;
		for (int u : edge[x]) if (!vis[u])
			q.emplace(u, len+1), vis[u] = true;
	}
	return inf;
}
int brute_cal() {
	cal_init();
	int res = 0;
	for (int i = 1;i <= n;++i) 
		res = max(res, bfs(i));
	return res;
}
void brute_solve() {
	int res = inf, p;
	for (int s = 0;s < 1<<n;++s) {
		bool ok = true;
		for (int i = 0;i < n;++i)
			if (c[i+1] != -1 && c[i+1] != (s>>i&1)) 
				ok = false;
		if (!ok) continue;
		DE(s);
		vector<int> oldc(c, c+n+1);
		for (int i = 0;i < n;++i)
			c[i+1] = s>>i&1;
		int val = brute_cal();
		chmin(res, val);
		if (res == val) p = s;
		copy(AI(oldc), c);
		
	}
	if (res > n) {
		assert(false);
		return cout << -1 << '\n', void();
	}

	cout << res << '\n';
	for (int i = 0;i < n;++i)
		cout << (p>>i&1) << " \n"[i+1==n];
}
void solve() {
	cin >> n;
	clear();
	for (int a, b, i = 1;i < n;++i) {
		cin >> a >> b;
		edge[a].pb(b);
		edge[b].pb(a);
	}

	for (int i = 1;i <= n;++i)
		cin >> c[i];

	int cn = count(c+1, c+n+1, -1), c0 = count(c+1, c+n+1, 0), c1 = count(c+1, c+n+1, 1);
	if ((c0==1) + (c1==1) > cn)
		return cout << -1 << '\n', void();

	if (n <= 17)
		return brute_solve(), void();

	if (cn == 0) {
		int val = cal();
		if (val > n)
			return cout << -1 << '\n', void();
		cout << cal() << '\n';
		for (int i = 1;i <= n;++i)
			cout << c[i] << " \n"[i==n];
	}
	else
		exit(1);
}

int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int T;
	cin >> T;
	while (T--)
		solve();
}

Compilation message

balancedtree.cpp: In function 'void brute_solve()':
balancedtree.cpp:14:17: warning: statement has no effect [-Wunused-value]
   14 | #define DE(...) 0
      |                 ^
balancedtree.cpp:113:3: note: in expansion of macro 'DE'
  113 |   DE(s);
      |   ^~
balancedtree.cpp:130:13: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
  130 |   cout << (p>>i&1) << " \n"[i+1==n];
      |            ~^~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 148 ms 12152 KB Output is correct
2 Correct 610 ms 12280 KB Output is correct

Subtask #2
0.0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 42 ms 12288 KB Output isn't correct
2 Incorrect 231 ms 14604 KB Output isn't correct
3 Incorrect 64 ms 12792 KB Output isn't correct

Subtask #3
0.0 / 26.0

# Verdict Execution time Memory Grader output
1 Runtime error 8 ms 12032 KB Execution failed because the return code was nonzero
2 Runtime error 51 ms 15608 KB Execution failed because the return code was nonzero
3 Runtime error 21 ms 13560 KB Execution failed because the return code was nonzero

Subtask #4
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Runtime error 16 ms 12800 KB Execution failed because the return code was nonzero
2 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
3 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
4 Runtime error 8 ms 12032 KB Execution failed because the return code was nonzero
5 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
6 Runtime error 10 ms 12288 KB Execution failed because the return code was nonzero
7 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
8 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
9 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero

Subtask #5
0.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 148 ms 12152 KB Output is correct
2 Correct 610 ms 12280 KB Output is correct
3 Incorrect 42 ms 12288 KB Output isn't correct
4 Incorrect 231 ms 14604 KB Output isn't correct
5 Incorrect 64 ms 12792 KB Output isn't correct
6 Runtime error 8 ms 12032 KB Execution failed because the return code was nonzero
7 Runtime error 51 ms 15608 KB Execution failed because the return code was nonzero
8 Runtime error 21 ms 13560 KB Execution failed because the return code was nonzero
9 Runtime error 16 ms 12800 KB Execution failed because the return code was nonzero
10 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
11 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
12 Runtime error 8 ms 12032 KB Execution failed because the return code was nonzero
13 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
14 Runtime error 10 ms 12288 KB Execution failed because the return code was nonzero
15 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
16 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
17 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero
18 Runtime error 12 ms 12416 KB Execution failed because the return code was nonzero
19 Runtime error 64 ms 15736 KB Execution failed because the return code was nonzero
20 Runtime error 7 ms 12160 KB Execution failed because the return code was nonzero
21 Runtime error 315 ms 30328 KB Execution failed because the return code was nonzero
22 Runtime error 8 ms 12160 KB Execution failed because the return code was nonzero