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Submission #444249

# Submission time Handle Problem Language Result Execution time Memory
444249 2021-07-13T12:36:13 Z parsabahrami The Xana coup (BOI21_xanadu) C++17
100 / 100
 139 ms 36644 KB 
/* I do it for the glory */
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 1e6 + 10, MOD = 1e9 + 7;
int n, C[N]; vector<int> adj[N]; ll dp[2][2][N]; // [root ro zadim ya na][root akharesh chie][root] :clown:

void DFS(int v, int p = -1) {
    if (SZ(adj[v]) < 2 && v > 1) {
        dp[0][C[v]][v] = 0;
        dp[0][C[v] ^ 1][v] = dp[1][C[v]][v] = MOD;
        dp[1][!C[v]][v] = 1;
        return;
    }
    for (int &u : adj[v])   
        if (u != p) DFS(u, v);
    ll c = 0, m = MOD;
    for (int &u : adj[v]) {
        if (u != p) {
            if (dp[1][0][u] <= dp[0][0][u]) 
                c++;
            m = min(m, abs(dp[1][0][u] - dp[0][0][u]));
        }
    }
    for (int &u : adj[v]) {
        if (u != p) {
            dp[0][(c & 1) ^ C[v]][v] += min(dp[1][0][u], dp[0][0][u]);
        }
    }
    dp[0][(c & 1) ^ C[v] ^ 1][v] = dp[0][(c & 1) ^ C[v]][v] + m;
    c = 0, m = MOD;
    for (int &u : adj[v]) {
        if (u != p) {
            if (dp[1][1][u] <= dp[0][1][u]) 
                c++;
            m = min(m, abs(dp[1][1][u] - dp[0][1][u]));
        }
    }
    for (int &u : adj[v]) {
        if (u != p) {
            dp[1][(c & 1) ^ C[v] ^ 1][v] += min(dp[1][1][u], dp[0][1][u]);
        }
    }
    dp[1][(c & 1) ^ C[v] ^ 1][v]++;
    dp[1][(c & 1) ^ C[v]][v] = dp[1][(c & 1) ^ C[v] ^ 1][v] + m;
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i < n; i++) {
        int u, v; scanf("%d%d", &u, &v);
        adj[u].push_back(v);
        adj[v].push_back(u);
    }    
    for (int i = 1; i <= n; i++) 
        scanf("%d", &C[i]);
    DFS(1);
    printf(min(dp[1][0][1], dp[0][0][1]) > n ? "impossible\n" : "%lld\n", min(dp[1][0][1], dp[0][0][1]));
    return 0;
}

Compilation message

xanadu.cpp: In function 'int main()':
xanadu.cpp:57:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
xanadu.cpp:59:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |         int u, v; scanf("%d%d", &u, &v);
      |                   ~~~~~^~~~~~~~~~~~~~~~
xanadu.cpp:64:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         scanf("%d", &C[i]);
      |         ~~~~~^~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23816 KB Output is correct
2 Correct 16 ms 23744 KB Output is correct
3 Correct 14 ms 23712 KB Output is correct
4 Correct 14 ms 23756 KB Output is correct
5 Correct 15 ms 23756 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23816 KB Output is correct
2 Correct 16 ms 23744 KB Output is correct
3 Correct 14 ms 23712 KB Output is correct
4 Correct 14 ms 23756 KB Output is correct
5 Correct 15 ms 23756 KB Output is correct
6 Correct 14 ms 23784 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 14 ms 23756 KB Output is correct
9 Correct 15 ms 23784 KB Output is correct
10 Correct 14 ms 23820 KB Output is correct
11 Correct 15 ms 23748 KB Output is correct
12 Correct 14 ms 23704 KB Output is correct
13 Correct 14 ms 23756 KB Output is correct
14 Correct 17 ms 23748 KB Output is correct
15 Correct 15 ms 23788 KB Output is correct
16 Correct 16 ms 23708 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 81 ms 36548 KB Output is correct
2 Correct 81 ms 36400 KB Output is correct
3 Correct 91 ms 36620 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 92 ms 36596 KB Output is correct
2 Correct 86 ms 36420 KB Output is correct
3 Correct 77 ms 36644 KB Output is correct
4 Correct 76 ms 29636 KB Output is correct
5 Correct 90 ms 30364 KB Output is correct
6 Correct 88 ms 30404 KB Output is correct
7 Correct 14 ms 23848 KB Output is correct
8 Correct 35 ms 25992 KB Output is correct
9 Correct 94 ms 30404 KB Output is correct
10 Correct 88 ms 30488 KB Output is correct
11 Correct 87 ms 30876 KB Output is correct
12 Correct 112 ms 30968 KB Output is correct
13 Correct 78 ms 29976 KB Output is correct
14 Correct 92 ms 30452 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23816 KB Output is correct
2 Correct 16 ms 23744 KB Output is correct
3 Correct 14 ms 23712 KB Output is correct
4 Correct 14 ms 23756 KB Output is correct
5 Correct 15 ms 23756 KB Output is correct
6 Correct 14 ms 23784 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 14 ms 23756 KB Output is correct
9 Correct 15 ms 23784 KB Output is correct
10 Correct 14 ms 23820 KB Output is correct
11 Correct 15 ms 23748 KB Output is correct
12 Correct 14 ms 23704 KB Output is correct
13 Correct 14 ms 23756 KB Output is correct
14 Correct 17 ms 23748 KB Output is correct
15 Correct 15 ms 23788 KB Output is correct
16 Correct 16 ms 23708 KB Output is correct
17 Correct 81 ms 36548 KB Output is correct
18 Correct 81 ms 36400 KB Output is correct
19 Correct 91 ms 36620 KB Output is correct
20 Correct 92 ms 36596 KB Output is correct
21 Correct 86 ms 36420 KB Output is correct
22 Correct 77 ms 36644 KB Output is correct
23 Correct 76 ms 29636 KB Output is correct
24 Correct 90 ms 30364 KB Output is correct
25 Correct 88 ms 30404 KB Output is correct
26 Correct 14 ms 23848 KB Output is correct
27 Correct 35 ms 25992 KB Output is correct
28 Correct 94 ms 30404 KB Output is correct
29 Correct 88 ms 30488 KB Output is correct
30 Correct 87 ms 30876 KB Output is correct
31 Correct 112 ms 30968 KB Output is correct
32 Correct 78 ms 29976 KB Output is correct
33 Correct 92 ms 30452 KB Output is correct
34 Correct 15 ms 23740 KB Output is correct
35 Correct 15 ms 23756 KB Output is correct
36 Correct 15 ms 23736 KB Output is correct
37 Correct 15 ms 23820 KB Output is correct
38 Correct 14 ms 23708 KB Output is correct
39 Correct 14 ms 23816 KB Output is correct
40 Correct 14 ms 23808 KB Output is correct
41 Correct 14 ms 23756 KB Output is correct
42 Correct 14 ms 23812 KB Output is correct
43 Correct 15 ms 23704 KB Output is correct
44 Correct 14 ms 23756 KB Output is correct
45 Correct 79 ms 36576 KB Output is correct
46 Correct 81 ms 36480 KB Output is correct
47 Correct 89 ms 36628 KB Output is correct
48 Correct 87 ms 29740 KB Output is correct
49 Correct 82 ms 30212 KB Output is correct
50 Correct 84 ms 30404 KB Output is correct
51 Correct 14 ms 23824 KB Output is correct
52 Correct 34 ms 25944 KB Output is correct
53 Correct 87 ms 30320 KB Output is correct
54 Correct 89 ms 30492 KB Output is correct
55 Correct 139 ms 30720 KB Output is correct
56 Correct 93 ms 30992 KB Output is correct
57 Correct 98 ms 29940 KB Output is correct
58 Correct 94 ms 30456 KB Output is correct
59 Correct 44 ms 25924 KB Output is correct
60 Correct 85 ms 29884 KB Output is correct
61 Correct 91 ms 30424 KB Output is correct
62 Correct 96 ms 30468 KB Output is correct
63 Correct 86 ms 30528 KB Output is correct
64 Correct 95 ms 30436 KB Output is correct
65 Correct 70 ms 30968 KB Output is correct
66 Correct 68 ms 30972 KB Output is correct
67 Correct 67 ms 30832 KB Output is correct
68 Correct 66 ms 30840 KB Output is correct
69 Correct 66 ms 30768 KB Output is correct
70 Correct 67 ms 30784 KB Output is correct