oj.uz

Submission #905039

# Submission time Handle Problem Language Result Execution time Memory
905039 2024-01-12T13:15:17 Z vjudge1 The Xana coup (BOI21_xanadu) C++17
100 / 100
 62 ms 17744 KB 
#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ld long double
#define pb push_back //emplace_back
#define pp pop_back
#define pii pair<ll, ll> //pair<int, int>
#define all(x) (x).begin(),(x).end()
#define mp(a,b) make_pair(a , b)
#define lb lower_bound
#define ub upper_bound
#define sz(x) (ll)(x).size()
#define F first
#define S second
#define bg(x) (x).begin()
#define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
#define debug(x) cout << #x << " : " << x << endl
#define endl '\n'
#define arr(x) array<int , (x)>
#define no cout << "impossible\n"
#define yes cout << "YES\n"
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);
#define INF 1000000000000000000
ll Sum(ll a , ll b , ll MOD)
{
 a %= MOD;
 b %= MOD;
 a += b;
 return a % MOD;
}

ll Mul(ll a , ll b , ll MOD)
{
 a %= MOD;
 b %= MOD;
 a *= b;
 return a % MOD;
}

ll Pow(ll a , ll b , ll MOD)
{
   ll res = 1;
   while(b)
   {
        if((b & 1))res = Mul(res , a , MOD);
     a = Mul(a , a , MOD);
     b >>= 1;
   }
   return res;
}

ll Min(ll a , ll b)
{
   if(a > b)return b;
   return a;
}

ll Max(ll a , ll b)
{
   if(a > b)return a;
   return b;
}

ll Ceil(ll a , ll b)
{
 if(a % b)return (a/b)+1;
 return a/b;
}

/////////////////////
//VALS
ll n;

const ll maxn = 1e5+1e3;
vector<ll> adj[maxn];

ll dp[maxn][2][2];
ll a[maxn];
/////////////////////
//FUNCTIONS
void dfs(ll i,ll par = -1) 
{
    dp[i][0][a[i]] = 0;
    dp[i][0][a[i] ^ 1] = INF;
    dp[i][1][a[i] ^ 1] = 1;
    dp[i][1][a[i]] = INF;
 
 	for (int j : adj[i])
    	if (j != par) 
		{
      		dfs(j, i);
      		for (int s = 0; s < 2; s++) 
			{
        		ll dp0 = dp[i][s][0], dp1 = dp[i][s][1];
        		dp[i][s][0] = Min(INF, Min(dp0 + dp[j][0][s], dp1 + dp[j][1][s]));
        		dp[i][s][1] = Min(INF, Min(dp0 + dp[j][1][s], dp1 + dp[j][0][s]));
      		}
    	}
    	
    	
}
/////////////////////
//SOLVE
void solve()
{
	cin >> n;
	
	For(i,n-1)
	{
		ll u, v;
		cin >> u >> v;
		u--;
		v--;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	
	For(i,n)cin >> a[i];
	
	dfs(0,0);
	
	if(dp[0][0][0] == dp[0][1][0] and dp[0][1][0] == INF)no;
	else
		cout << Min(dp[0][0][0], dp[0][1][0]) << endl;
}
/////////////////////
//MAIN
int main()
{
    FAST;
    ll t = 1;
//    cin >> t;
    while(t--)
    {
        solve();
    }
}
/////////////////////
/*
ZZZZZZZ     A        M     M     IIIIIII  N     N
     Z     A A      M M   M M       I     NN    N
    Z     A   A    M   M M   M      I     N N   N
   Z     AAAAAAA  M     M     M     I     N  N  N
  Z      A     A  M           M     I     N   N N
 Z       A     A  M           M     I     N    NN
ZZZZZZZ  A     A  M           M  IIIIIII  N     N  TREE
*/

Compilation message

xanadu.cpp: In function 'void solve()':
xanadu.cpp:20:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   20 | #define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
      |                           ^
xanadu.cpp:112:2: note: in expansion of macro 'For'
  112 |  For(i,n-1)
      |  ^~~
xanadu.cpp:20:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   20 | #define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
      |                           ^
xanadu.cpp:122:2: note: in expansion of macro 'For'
  122 |  For(i,n)cin >> a[i];
      |  ^~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6488 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6488 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct
6 Correct 2 ms 6492 KB Output is correct
7 Correct 2 ms 6492 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 2 ms 6492 KB Output is correct
10 Correct 2 ms 6492 KB Output is correct
11 Correct 3 ms 6492 KB Output is correct
12 Correct 2 ms 6488 KB Output is correct
13 Correct 2 ms 6492 KB Output is correct
14 Correct 2 ms 6492 KB Output is correct
15 Correct 2 ms 6492 KB Output is correct
16 Correct 3 ms 6492 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 37 ms 17628 KB Output is correct
2 Correct 37 ms 17484 KB Output is correct
3 Correct 62 ms 17716 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 17500 KB Output is correct
2 Correct 48 ms 17336 KB Output is correct
3 Correct 50 ms 17492 KB Output is correct
4 Correct 52 ms 10320 KB Output is correct
5 Correct 40 ms 10576 KB Output is correct
6 Correct 37 ms 10592 KB Output is correct
7 Correct 3 ms 6492 KB Output is correct
8 Correct 11 ms 8028 KB Output is correct
9 Correct 47 ms 10368 KB Output is correct
10 Correct 44 ms 10276 KB Output is correct
11 Correct 34 ms 10928 KB Output is correct
12 Correct 33 ms 11056 KB Output is correct
13 Correct 31 ms 10588 KB Output is correct
14 Correct 32 ms 10836 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6488 KB Output is correct
5 Correct 2 ms 6488 KB Output is correct
6 Correct 2 ms 6492 KB Output is correct
7 Correct 2 ms 6492 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 2 ms 6492 KB Output is correct
10 Correct 2 ms 6492 KB Output is correct
11 Correct 3 ms 6492 KB Output is correct
12 Correct 2 ms 6488 KB Output is correct
13 Correct 2 ms 6492 KB Output is correct
14 Correct 2 ms 6492 KB Output is correct
15 Correct 2 ms 6492 KB Output is correct
16 Correct 3 ms 6492 KB Output is correct
17 Correct 37 ms 17628 KB Output is correct
18 Correct 37 ms 17484 KB Output is correct
19 Correct 62 ms 17716 KB Output is correct
20 Correct 38 ms 17500 KB Output is correct
21 Correct 48 ms 17336 KB Output is correct
22 Correct 50 ms 17492 KB Output is correct
23 Correct 52 ms 10320 KB Output is correct
24 Correct 40 ms 10576 KB Output is correct
25 Correct 37 ms 10592 KB Output is correct
26 Correct 3 ms 6492 KB Output is correct
27 Correct 11 ms 8028 KB Output is correct
28 Correct 47 ms 10368 KB Output is correct
29 Correct 44 ms 10276 KB Output is correct
30 Correct 34 ms 10928 KB Output is correct
31 Correct 33 ms 11056 KB Output is correct
32 Correct 31 ms 10588 KB Output is correct
33 Correct 32 ms 10836 KB Output is correct
34 Correct 3 ms 6492 KB Output is correct
35 Correct 2 ms 6492 KB Output is correct
36 Correct 3 ms 6492 KB Output is correct
37 Correct 2 ms 6492 KB Output is correct
38 Correct 2 ms 6492 KB Output is correct
39 Correct 2 ms 6492 KB Output is correct
40 Correct 2 ms 6492 KB Output is correct
41 Correct 2 ms 6492 KB Output is correct
42 Correct 2 ms 6492 KB Output is correct
43 Correct 2 ms 6492 KB Output is correct
44 Correct 2 ms 6492 KB Output is correct
45 Correct 44 ms 17744 KB Output is correct
46 Correct 37 ms 17520 KB Output is correct
47 Correct 39 ms 17560 KB Output is correct
48 Correct 29 ms 10332 KB Output is correct
49 Correct 42 ms 10456 KB Output is correct
50 Correct 42 ms 10576 KB Output is correct
51 Correct 2 ms 6492 KB Output is correct
52 Correct 17 ms 8032 KB Output is correct
53 Correct 35 ms 10320 KB Output is correct
54 Correct 47 ms 10332 KB Output is correct
55 Correct 37 ms 10844 KB Output is correct
56 Correct 50 ms 11088 KB Output is correct
57 Correct 30 ms 10588 KB Output is correct
58 Correct 32 ms 11096 KB Output is correct
59 Correct 17 ms 7772 KB Output is correct
60 Correct 43 ms 9820 KB Output is correct
61 Correct 46 ms 10380 KB Output is correct
62 Correct 32 ms 10320 KB Output is correct
63 Correct 56 ms 10508 KB Output is correct
64 Correct 41 ms 10320 KB Output is correct
65 Correct 44 ms 10948 KB Output is correct
66 Correct 32 ms 10836 KB Output is correct
67 Correct 26 ms 10700 KB Output is correct
68 Correct 37 ms 10956 KB Output is correct
69 Correct 27 ms 10480 KB Output is correct
70 Correct 31 ms 10440 KB Output is correct