oj.uz

Submission #676617

# Submission time Handle Problem Language Result Execution time Memory
676617 2022-12-31T12:59:52 Z YENGOYAN The Xana coup (BOI21_xanadu) C++17
100 / 100
 90 ms 16888 KB 
/*
	//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\\
	\\                                    //
	//  271828___182845__904523__53602__  \\
	\\  87___47____13______52____66__24_  //
	//  97___75____72______47____09___36  \\
	\\  999595_____74______96____69___67  //
	//  62___77____24______07____66__30_  \\
	\\  35___35____47______59____45713__  //
	//                                    \\
	\\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\//
											  */

#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_map>
#include <cmath>
#include <climits>
#include <algorithm>
#include <random>
#include <queue>
#include <deque>
#include <iomanip>
#include <string>
#include <tuple>
#include <bitset>
#include <chrono>
#include <ctime>
#include <fstream>
#include <stack>
#include <cstdio>

using namespace std;
using ll = long long;
const int N = 1e5 + 5;
const ll mod = 1e9 + 7, inf = 1e12;

int n;
ll dp[N][2][2];
vector<vector<int>> gp;
vector<int> col;

void dfs(int u, int p) {
	for (int& v : gp[u]) {
		if (v != p) dfs(v, u);
	}
	int cnt_child = gp[u].size() - (u != 0);
	if (!cnt_child) {
		if (col[u]) {
			dp[u][0][0] = 0;
			dp[u][1][1] = 1;
			dp[u][0][1] = dp[u][1][0] = inf;
		}
		else {
			dp[u][0][0] = dp[u][1][1] = inf;
			dp[u][0][1] = 0;
			dp[u][1][0] = 1;
		}
		return;
	}
	// dp[u][i][j]
	// i -> gagat, j -> cnox
	ll res = 0, mn = 2e9, cnt = 0;
	for (int v : gp[u]) {
		if (v == p) continue;	
		res += min(dp[v][0][0], dp[v][1][0]);
		if (dp[v][1][0] <= dp[v][0][0]) {
			++cnt;
		}
		mn = min(mn, abs(dp[v][0][0] - dp[v][1][0]));
	}
	if (col[u] && cnt % 2) dp[u][0][0] = res + mn;
	else if (!col[u] && cnt % 2 == 0) dp[u][0][0] = res + mn;
	else dp[u][0][0] = res;
	if (!col[u] && cnt % 2) dp[u][0][1] = res + mn;
	else if (col[u] && cnt % 2 == 0) dp[u][0][1] = res + mn;
	else dp[u][0][1] = res;
	res = 0, mn = 2e9, cnt = 0;
	for (int& v : gp[u]) {
		if (v == p) continue;
		res += min(dp[v][0][1], dp[v][1][1]);
		if (dp[v][1][1] <= dp[v][0][1]) ++cnt;
		mn = min(mn, abs(dp[v][0][1] - dp[v][1][1]));
	}
	if (col[u] && cnt % 2 == 0) dp[u][1][0] = res + mn + 1;
	else if (!col[u] && cnt % 2) dp[u][1][0] = res + mn + 1;
	else dp[u][1][0] = res + 1;
	if (!col[u] && cnt % 2 == 0) dp[u][1][1] = res + mn + 1;
	else if (col[u] && cnt % 2) dp[u][1][1] = res + mn + 1;
	else dp[u][1][1] = res + 1;
	//if(!u)
}

void solve() {
	cin >> n;
	gp = vector<vector<int>>(n);
	col = vector<int>(n);
	for (int i = 1; i < n; ++i) {
		int u, v; cin >> u >> v;
		gp[--u].push_back(--v);
		gp[v].push_back(u);
	}
	for (int i = 0; i < n; ++i)  cin >> col[i], col[i] = !col[i];
	dfs(0, -1);
	/*for (int i = 0; i < n; ++i) {
		cout << dp[i][0][0] << " " << dp[i][0][1] << " " << dp[i][1][0] << " " << dp[i][1][1] << "\n";
	}*/
	ll res = min(dp[0][0][0], dp[0][1][0]);
	if (res > n) cout << "impossible\n";
	else cout << res << "\n";
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);
	//int ; cin >> _; while (--)
	solve();
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 336 KB Output is correct
13 Correct 0 ms 336 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 50 ms 16720 KB Output is correct
2 Correct 44 ms 16588 KB Output is correct
3 Correct 55 ms 16888 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 16724 KB Output is correct
2 Correct 58 ms 16608 KB Output is correct
3 Correct 69 ms 16860 KB Output is correct
4 Correct 62 ms 9460 KB Output is correct
5 Correct 48 ms 10332 KB Output is correct
6 Correct 50 ms 10664 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 14 ms 3708 KB Output is correct
9 Correct 59 ms 10472 KB Output is correct
10 Correct 52 ms 10620 KB Output is correct
11 Correct 79 ms 11040 KB Output is correct
12 Correct 56 ms 11208 KB Output is correct
13 Correct 44 ms 9904 KB Output is correct
14 Correct 50 ms 10636 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 336 KB Output is correct
13 Correct 0 ms 336 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 50 ms 16720 KB Output is correct
18 Correct 44 ms 16588 KB Output is correct
19 Correct 55 ms 16888 KB Output is correct
20 Correct 45 ms 16724 KB Output is correct
21 Correct 58 ms 16608 KB Output is correct
22 Correct 69 ms 16860 KB Output is correct
23 Correct 62 ms 9460 KB Output is correct
24 Correct 48 ms 10332 KB Output is correct
25 Correct 50 ms 10664 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 14 ms 3708 KB Output is correct
28 Correct 59 ms 10472 KB Output is correct
29 Correct 52 ms 10620 KB Output is correct
30 Correct 79 ms 11040 KB Output is correct
31 Correct 56 ms 11208 KB Output is correct
32 Correct 44 ms 9904 KB Output is correct
33 Correct 50 ms 10636 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 1 ms 324 KB Output is correct
36 Correct 1 ms 212 KB Output is correct
37 Correct 1 ms 212 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 1 ms 340 KB Output is correct
40 Correct 1 ms 212 KB Output is correct
41 Correct 0 ms 212 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 1 ms 212 KB Output is correct
44 Correct 1 ms 212 KB Output is correct
45 Correct 45 ms 16724 KB Output is correct
46 Correct 44 ms 16544 KB Output is correct
47 Correct 66 ms 16844 KB Output is correct
48 Correct 42 ms 9548 KB Output is correct
49 Correct 56 ms 10444 KB Output is correct
50 Correct 63 ms 10620 KB Output is correct
51 Correct 1 ms 340 KB Output is correct
52 Correct 14 ms 3712 KB Output is correct
53 Correct 50 ms 10444 KB Output is correct
54 Correct 63 ms 10724 KB Output is correct
55 Correct 61 ms 10908 KB Output is correct
56 Correct 79 ms 11220 KB Output is correct
57 Correct 55 ms 9900 KB Output is correct
58 Correct 47 ms 10656 KB Output is correct
59 Correct 19 ms 3672 KB Output is correct
60 Correct 58 ms 9548 KB Output is correct
61 Correct 64 ms 10520 KB Output is correct
62 Correct 90 ms 10744 KB Output is correct
63 Correct 65 ms 10696 KB Output is correct
64 Correct 73 ms 10644 KB Output is correct
65 Correct 41 ms 11164 KB Output is correct
66 Correct 43 ms 11132 KB Output is correct
67 Correct 53 ms 10972 KB Output is correct
68 Correct 39 ms 11072 KB Output is correct
69 Correct 44 ms 11120 KB Output is correct
70 Correct 35 ms 11072 KB Output is correct