oj.uz

Submission #424795

# Submission time Handle Problem Language Result Execution time Memory
424795 2021-06-12T10:21:27 Z zoooma13 The Xana coup (BOI21_xanadu) C++14
100 / 100
 150 ms 24768 KB 
#include <bits/stdc++.h>
using namespace std;

#define MAX_N 100005

vector <int> state;
vector <vector <int>> adj;

int dp[2][2][MAX_N];
int dfs(int u ,bool st ,bool sp ,int p){
    if(adj[u].size() == 1 && p != -1)
        return (state[u]^sp) == st? st : MAX_N;
    auto&ret = dp[st][sp][u];
    if(~ret)
        return ret;
    ret = MAX_N;
    vector <pair<int ,int>> chld;
    for(int&v : adj[u]) if(v != p)
        chld.push_back({dfs(v ,0 ,st ,u) ,dfs(v ,1 ,st ,u)});
    sort(chld.begin() ,chld.end() ,[](auto&i ,auto&j){
        return i.second-i.first < j.second-j.first;
    });
    int64_t tot = 0;
    for(int i = 0; i < chld.size(); i++)
        tot += chld[i].first;
    int j = 0;
    if((state[u]^sp) != st)
        tot += chld[j].second - chld[j].first ,j++;
    ret = min((int64_t)ret ,tot);
    while(j < chld.size()){
        tot += chld[j].second - chld[j].first ,j++;
        if(j == chld.size()) break;
        tot += chld[j].second - chld[j].first ,j++;
        ret = min((int64_t)ret ,tot);
    }
    return ret = ret + st;
}

int main()
{
    int n;
    scanf("%d",&n);
    adj.resize(n+1);
    state.resize(n+1);
    for(int a ,b ,i = 1; i < n; i++){
        scanf("%d%d",&a,&b);
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i = 1; i <= n; i++)
        scanf("%d",&state[i]);

    memset(dp ,-1 ,sizeof dp);
    int ans = min(dfs(1 ,0 ,0 ,-1) ,dfs(1 ,1 ,0 ,-1));
    printf(ans >= MAX_N? "impossible\n" : "%d\n",ans);
}

Compilation message

xanadu.cpp: In function 'int dfs(int, bool, bool, int)':
xanadu.cpp:24:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |     for(int i = 0; i < chld.size(); i++)
      |                    ~~^~~~~~~~~~~~~
xanadu.cpp:30:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     while(j < chld.size()){
      |           ~~^~~~~~~~~~~~~
xanadu.cpp:32:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         if(j == chld.size()) break;
      |            ~~^~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
xanadu.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         scanf("%d%d",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~
xanadu.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         scanf("%d",&state[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1740 KB Output is correct
2 Correct 1 ms 1740 KB Output is correct
3 Correct 1 ms 1832 KB Output is correct
4 Correct 1 ms 1740 KB Output is correct
5 Correct 1 ms 1740 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1740 KB Output is correct
2 Correct 1 ms 1740 KB Output is correct
3 Correct 1 ms 1832 KB Output is correct
4 Correct 1 ms 1740 KB Output is correct
5 Correct 1 ms 1740 KB Output is correct
6 Correct 1 ms 1740 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 1 ms 1868 KB Output is correct
9 Correct 1 ms 1868 KB Output is correct
10 Correct 2 ms 1820 KB Output is correct
11 Correct 2 ms 1868 KB Output is correct
12 Correct 1 ms 1868 KB Output is correct
13 Correct 1 ms 1868 KB Output is correct
14 Correct 1 ms 1868 KB Output is correct
15 Correct 1 ms 1868 KB Output is correct
16 Correct 1 ms 1868 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 102 ms 23260 KB Output is correct
2 Correct 113 ms 24288 KB Output is correct
3 Correct 106 ms 24768 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 108 ms 23240 KB Output is correct
2 Correct 118 ms 24240 KB Output is correct
3 Correct 109 ms 24612 KB Output is correct
4 Correct 111 ms 8216 KB Output is correct
5 Correct 121 ms 8936 KB Output is correct
6 Correct 124 ms 8964 KB Output is correct
7 Correct 2 ms 1868 KB Output is correct
8 Correct 30 ms 4268 KB Output is correct
9 Correct 112 ms 9172 KB Output is correct
10 Correct 105 ms 9160 KB Output is correct
11 Correct 113 ms 10284 KB Output is correct
12 Correct 117 ms 10640 KB Output is correct
13 Correct 91 ms 8512 KB Output is correct
14 Correct 96 ms 8968 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1740 KB Output is correct
2 Correct 1 ms 1740 KB Output is correct
3 Correct 1 ms 1832 KB Output is correct
4 Correct 1 ms 1740 KB Output is correct
5 Correct 1 ms 1740 KB Output is correct
6 Correct 1 ms 1740 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 1 ms 1868 KB Output is correct
9 Correct 1 ms 1868 KB Output is correct
10 Correct 2 ms 1820 KB Output is correct
11 Correct 2 ms 1868 KB Output is correct
12 Correct 1 ms 1868 KB Output is correct
13 Correct 1 ms 1868 KB Output is correct
14 Correct 1 ms 1868 KB Output is correct
15 Correct 1 ms 1868 KB Output is correct
16 Correct 1 ms 1868 KB Output is correct
17 Correct 102 ms 23260 KB Output is correct
18 Correct 113 ms 24288 KB Output is correct
19 Correct 106 ms 24768 KB Output is correct
20 Correct 108 ms 23240 KB Output is correct
21 Correct 118 ms 24240 KB Output is correct
22 Correct 109 ms 24612 KB Output is correct
23 Correct 111 ms 8216 KB Output is correct
24 Correct 121 ms 8936 KB Output is correct
25 Correct 124 ms 8964 KB Output is correct
26 Correct 2 ms 1868 KB Output is correct
27 Correct 30 ms 4268 KB Output is correct
28 Correct 112 ms 9172 KB Output is correct
29 Correct 105 ms 9160 KB Output is correct
30 Correct 113 ms 10284 KB Output is correct
31 Correct 117 ms 10640 KB Output is correct
32 Correct 91 ms 8512 KB Output is correct
33 Correct 96 ms 8968 KB Output is correct
34 Correct 1 ms 1868 KB Output is correct
35 Correct 1 ms 1740 KB Output is correct
36 Correct 2 ms 1740 KB Output is correct
37 Correct 2 ms 1752 KB Output is correct
38 Correct 1 ms 1740 KB Output is correct
39 Correct 1 ms 1868 KB Output is correct
40 Correct 1 ms 1868 KB Output is correct
41 Correct 1 ms 1868 KB Output is correct
42 Correct 2 ms 1868 KB Output is correct
43 Correct 1 ms 1868 KB Output is correct
44 Correct 1 ms 1740 KB Output is correct
45 Correct 117 ms 24516 KB Output is correct
46 Correct 99 ms 24264 KB Output is correct
47 Correct 144 ms 24644 KB Output is correct
48 Correct 96 ms 8308 KB Output is correct
49 Correct 99 ms 8924 KB Output is correct
50 Correct 114 ms 9048 KB Output is correct
51 Correct 2 ms 1868 KB Output is correct
52 Correct 42 ms 4300 KB Output is correct
53 Correct 150 ms 9104 KB Output is correct
54 Correct 115 ms 9284 KB Output is correct
55 Correct 106 ms 10308 KB Output is correct
56 Correct 119 ms 10544 KB Output is correct
57 Correct 107 ms 8620 KB Output is correct
58 Correct 108 ms 9068 KB Output is correct
59 Correct 34 ms 4312 KB Output is correct
60 Correct 87 ms 8388 KB Output is correct
61 Correct 102 ms 9064 KB Output is correct
62 Correct 95 ms 9212 KB Output is correct
63 Correct 128 ms 9284 KB Output is correct
64 Correct 109 ms 9220 KB Output is correct
65 Correct 71 ms 9516 KB Output is correct
66 Correct 69 ms 9540 KB Output is correct
67 Correct 78 ms 11252 KB Output is correct
68 Correct 98 ms 11288 KB Output is correct
69 Correct 82 ms 11260 KB Output is correct
70 Correct 90 ms 11232 KB Output is correct