oj.uz

Submission #729724

# Submission time Handle Problem Language Result Execution time Memory
729724 2023-04-24T12:09:27 Z Sam_a17 The Xana coup (BOI21_xanadu) C++17
100 / 100
 88 ms 27144 KB 
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int)x.size()
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount

#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long

void print(long long t) { cerr << t; }
void print(int t) { cerr << t; }
void print(string t) { cerr << t; }
void print(char t) { cerr << t; }
void print(double t) { cerr << t; }
void print(long double t) { cerr << t; }
void print(unsigned long long t) { cerr << t; }

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[], V n) { cerr << "["; for (int i = 0; i < n; i++) { print(v[i]); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(pair <T, V> p) { cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}"; }
template <class T> void print(vector <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(set <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(multiset <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(unordered_map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(deque <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);

// for grid problems
int dx[8] = { -1,0,1,0,1,-1,1,-1 };
int dy[8] = { 0,1,0,-1,1,1,-1,-1 };

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
	fastIO();

	if (str == "input") {
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	}
	else {
		// freopen("skis.in", "r", stdin);
		// freopen("skis.out", "w", stdout);
	}
}
// Indexed Set  
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2e5 + 10, inf = 1e8;
long long dp[N][2][2];
vector<int> adj[N];
int n, a[N];

void dfs(int node, int parent) {
	dp[node][0][a[node]] = 0;
	dp[node][1][a[node] ^ 1] = 1;

	for(auto i: adj[node]) {
		if(i == parent) continue;
		dfs(i, node);

		vector<vector<long long>> new_dp(2, vector<long long> (2, inf));
		if(dp[i][0][0] != inf) {
			new_dp[0][0] = min(new_dp[0][0], dp[node][0][0] + dp[i][0][0]);
			new_dp[0][1] = min(new_dp[0][1], dp[node][0][1] + dp[i][0][0]);
		} 

		if(dp[i][0][1] != inf) {
			new_dp[1][0] = min(new_dp[1][0], dp[node][1][0] + dp[i][0][1]);
			new_dp[1][1] = min(new_dp[1][1], dp[node][1][1] + dp[i][0][1]);
		} 

		if(dp[i][1][0] != inf) {
			new_dp[0][0] = min(new_dp[0][0], dp[node][0][1] + dp[i][1][0]);
			new_dp[0][1] = min(new_dp[0][1], dp[node][0][0] + dp[i][1][0]);
		} 

		if(dp[i][1][1] != inf) {
			new_dp[1][0] = min(new_dp[1][0], dp[node][1][1] + dp[i][1][1]);
			new_dp[1][1] = min(new_dp[1][1], dp[node][1][0] + dp[i][1][1]);
		}


		for(int j = 0; j < 2; j++) {
			for(int k = 0; k < 2; k++) {
				dp[node][j][k] = new_dp[j][k];
			}
		}
	}
}

void solve_() {
	cin >> n;
	for(int i = 1; i <= n - 1; i++) {
		int x, y; cin >> x >> y;
		adj[x].push_back(y);
		adj[y].push_back(x);
	}
	
	for(int i = 1; i <= n; i++) {
		for(int j = 0; j <= 1; j++) {
			for(int k = 0; k <= 1; k++) {
				dp[i][j][k] = inf;
			}
		}
	}

	for(int i = 1; i <= n; i++) {
		cin >> a[i];
	}

	dfs(1, 0);

	long long ans = min(dp[1][0][0], dp[1][1][0]);
	if(ans < inf) {
		cout << ans << '\n';
	} else {
		cout << "impossible" << '\n';
	}
}

int main() {
	setIO();

	auto solve = [&](int test_case)-> void {
		for (int i = 1; i <= test_case; i++) {
			solve_();
		}
	};

	int test_cases = 1;
	// cin >> test_cases;
	solve(test_cases);

	return 0;
}

Compilation message

xanadu.cpp: In function 'void setIO(std::string)':
xanadu.cpp:69:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |   freopen("input.txt", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
xanadu.cpp:70:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   freopen("output.txt", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5036 KB Output is correct
2 Correct 4 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 5 ms 5064 KB Output is correct
5 Correct 4 ms 4948 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5036 KB Output is correct
2 Correct 4 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 5 ms 5064 KB Output is correct
5 Correct 4 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 5036 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 5032 KB Output is correct
15 Correct 4 ms 5040 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 88 ms 26988 KB Output is correct
2 Correct 83 ms 26680 KB Output is correct
3 Correct 64 ms 27112 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 79 ms 26984 KB Output is correct
2 Correct 65 ms 26800 KB Output is correct
3 Correct 72 ms 27144 KB Output is correct
4 Correct 79 ms 12124 KB Output is correct
5 Correct 72 ms 12776 KB Output is correct
6 Correct 67 ms 12984 KB Output is correct
7 Correct 3 ms 5076 KB Output is correct
8 Correct 20 ms 7732 KB Output is correct
9 Correct 71 ms 13008 KB Output is correct
10 Correct 65 ms 13068 KB Output is correct
11 Correct 63 ms 13992 KB Output is correct
12 Correct 64 ms 14284 KB Output is correct
13 Correct 54 ms 12480 KB Output is correct
14 Correct 76 ms 13024 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5036 KB Output is correct
2 Correct 4 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 5 ms 5064 KB Output is correct
5 Correct 4 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 5036 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 5032 KB Output is correct
15 Correct 4 ms 5040 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 88 ms 26988 KB Output is correct
18 Correct 83 ms 26680 KB Output is correct
19 Correct 64 ms 27112 KB Output is correct
20 Correct 79 ms 26984 KB Output is correct
21 Correct 65 ms 26800 KB Output is correct
22 Correct 72 ms 27144 KB Output is correct
23 Correct 79 ms 12124 KB Output is correct
24 Correct 72 ms 12776 KB Output is correct
25 Correct 67 ms 12984 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 20 ms 7732 KB Output is correct
28 Correct 71 ms 13008 KB Output is correct
29 Correct 65 ms 13068 KB Output is correct
30 Correct 63 ms 13992 KB Output is correct
31 Correct 64 ms 14284 KB Output is correct
32 Correct 54 ms 12480 KB Output is correct
33 Correct 76 ms 13024 KB Output is correct
34 Correct 3 ms 4948 KB Output is correct
35 Correct 3 ms 5032 KB Output is correct
36 Correct 3 ms 4948 KB Output is correct
37 Correct 3 ms 4948 KB Output is correct
38 Correct 3 ms 4948 KB Output is correct
39 Correct 3 ms 4948 KB Output is correct
40 Correct 3 ms 4948 KB Output is correct
41 Correct 3 ms 4948 KB Output is correct
42 Correct 3 ms 4948 KB Output is correct
43 Correct 3 ms 5036 KB Output is correct
44 Correct 3 ms 4948 KB Output is correct
45 Correct 69 ms 26928 KB Output is correct
46 Correct 76 ms 26624 KB Output is correct
47 Correct 65 ms 27092 KB Output is correct
48 Correct 56 ms 12068 KB Output is correct
49 Correct 68 ms 12752 KB Output is correct
50 Correct 70 ms 12976 KB Output is correct
51 Correct 3 ms 5016 KB Output is correct
52 Correct 19 ms 7740 KB Output is correct
53 Correct 61 ms 12956 KB Output is correct
54 Correct 61 ms 13176 KB Output is correct
55 Correct 58 ms 13976 KB Output is correct
56 Correct 60 ms 14240 KB Output is correct
57 Correct 60 ms 12516 KB Output is correct
58 Correct 59 ms 12984 KB Output is correct
59 Correct 18 ms 7608 KB Output is correct
60 Correct 61 ms 12268 KB Output is correct
61 Correct 69 ms 12980 KB Output is correct
62 Correct 77 ms 13136 KB Output is correct
63 Correct 69 ms 13076 KB Output is correct
64 Correct 57 ms 13056 KB Output is correct
65 Correct 61 ms 13472 KB Output is correct
66 Correct 59 ms 13568 KB Output is correct
67 Correct 46 ms 13376 KB Output is correct
68 Correct 53 ms 13356 KB Output is correct
69 Correct 49 ms 13380 KB Output is correct
70 Correct 47 ms 13428 KB Output is correct