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Submission #408954

# Submission time Handle Problem Language Result Execution time Memory
408954 2021-05-19T22:10:05 Z ly20 The Xana coup (BOI21_xanadu) C++17
100 / 100
 83 ms 20296 KB 
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 112345;
long long INF = 1123456789;
vector <int> grafo[MAXN];
int tp[MAXN];
long long dp[MAXN][2][2];
void dfs(int v, int p) {
    for(int i = 0; i < grafo[v].size(); i++) {
        int viz = grafo[v][i];
        if(viz == p) continue;
        dfs(viz, v);
    }
    long long cur[2][2];
    bool fl = 0;
    for(int i = 0; i < grafo[v].size(); i++) {
        int viz = grafo[v][i];
        if(viz == p) continue;
        //printf("%d\n", v);
        if(fl == 0) {
                //printf("%d\n", fl);
            cur[0][0] = dp[viz][0][0]; cur[0][1] = dp[viz][0][1];
            cur[1][0] = dp[viz][1][0]; cur[1][1] = dp[viz][1][1];
            fl = 1;
        }
        else {
                //printf("oi\n");
            long long temp[2][2];
            temp[0][0] = min(cur[0][0] + dp[viz][0][0], cur[0][1] + dp[viz][0][1]);
            temp[0][1] = min(cur[0][1] + dp[viz][0][0], cur[0][0] + dp[viz][0][1]);
            temp[1][0] = min(cur[1][0] + dp[viz][1][0], cur[1][1] + dp[viz][1][1]);
            temp[1][1] = min(cur[1][1] + dp[viz][1][0], cur[1][0] + dp[viz][1][1]);
            cur[0][0] = temp[0][0]; cur[0][1] = temp[0][1];
            cur[1][0] = temp[1][0]; cur[1][1] = temp[1][1];
            //printf("%d %d %d %d %d\n", v, temp[0][0], temp[0][1], temp[1][0], temp[1][1]);
        }
    }
    if(fl == 0) {
        //printf("%d\n", v);
        if(tp[v] == 0) {
                //printf("%d\n", v);
            dp[v][0][0] = 0LL;
            dp[v][0][1] = INF;
            dp[v][1][0] = INF;
            dp[v][1][1] = 1LL;
        }
        else {
            dp[v][0][0] = INF;
            dp[v][0][1] = 1LL;
            dp[v][1][0] = 0LL;
            dp[v][1][1] = INF;
        }
        //printf("%d %lld %lld %lld %lld\n", v, dp[v][0][0], dp[v][1][0], dp[v][0][1], dp[v][1][1]);
    }
    else {
        if(tp[v] == 0) {
            dp[v][0][0] = cur[0][0];
            dp[v][0][1] = cur[1][1] + 1;
            dp[v][1][0] = cur[0][1];
            dp[v][1][1] = cur[1][0] + 1;
        }
        else {
            dp[v][0][0] = cur[0][1];
            dp[v][0][1] = cur[1][0] + 1;
            dp[v][1][0] = cur[0][0];
            dp[v][1][1] = cur[1][1] + 1;
        }
    }
    //printf("%d %lld %lld %lld %lld\n", v, dp[v][0][0], dp[v][1][0], dp[v][0][1], dp[v][1][1]);
}
int main() {
    int n;
    scanf("%d", &n);
    for(int i = 0; i < n - 1; i++) {
        int a, b;
        scanf("%d %d", &a, &b);
        grafo[a].push_back(b); grafo[b].push_back(a);
    }
    for(int i = 1; i <= n; i++) scanf("%d", &tp[i]);
    dfs(1, 1);
    if(min(dp[1][0][0], dp[1][0][1]) < INF) printf("%lld\n", min(dp[1][0][0], dp[1][0][1]));
    else printf("impossible\n");
}

Compilation message

xanadu.cpp: In function 'void dfs(int, int)':
xanadu.cpp:9:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for(int i = 0; i < grafo[v].size(); i++) {
      |                    ~~^~~~~~~~~~~~~~~~~
xanadu.cpp:16:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for(int i = 0; i < grafo[v].size(); i++) {
      |                    ~~^~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
xanadu.cpp:76:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         scanf("%d %d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~~
xanadu.cpp:79:38: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |     for(int i = 1; i <= n; i++) scanf("%d", &tp[i]);
      |                                 ~~~~~^~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2892 KB Output is correct
2 Correct 2 ms 2892 KB Output is correct
3 Correct 2 ms 2944 KB Output is correct
4 Correct 2 ms 2948 KB Output is correct
5 Correct 2 ms 2892 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2892 KB Output is correct
2 Correct 2 ms 2892 KB Output is correct
3 Correct 2 ms 2944 KB Output is correct
4 Correct 2 ms 2948 KB Output is correct
5 Correct 2 ms 2892 KB Output is correct
6 Correct 2 ms 2892 KB Output is correct
7 Correct 2 ms 2892 KB Output is correct
8 Correct 2 ms 2948 KB Output is correct
9 Correct 2 ms 2940 KB Output is correct
10 Correct 2 ms 2892 KB Output is correct
11 Correct 2 ms 2892 KB Output is correct
12 Correct 2 ms 2948 KB Output is correct
13 Correct 3 ms 2928 KB Output is correct
14 Correct 2 ms 2892 KB Output is correct
15 Correct 3 ms 2892 KB Output is correct
16 Correct 2 ms 2892 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 82 ms 20140 KB Output is correct
2 Correct 64 ms 19908 KB Output is correct
3 Correct 68 ms 20296 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 20208 KB Output is correct
2 Correct 75 ms 19908 KB Output is correct
3 Correct 80 ms 20268 KB Output is correct
4 Correct 63 ms 9976 KB Output is correct
5 Correct 76 ms 10692 KB Output is correct
6 Correct 77 ms 10884 KB Output is correct
7 Correct 3 ms 2876 KB Output is correct
8 Correct 21 ms 5608 KB Output is correct
9 Correct 80 ms 10756 KB Output is correct
10 Correct 79 ms 11076 KB Output is correct
11 Correct 72 ms 11452 KB Output is correct
12 Correct 83 ms 11720 KB Output is correct
13 Correct 67 ms 10304 KB Output is correct
14 Correct 73 ms 10804 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2892 KB Output is correct
2 Correct 2 ms 2892 KB Output is correct
3 Correct 2 ms 2944 KB Output is correct
4 Correct 2 ms 2948 KB Output is correct
5 Correct 2 ms 2892 KB Output is correct
6 Correct 2 ms 2892 KB Output is correct
7 Correct 2 ms 2892 KB Output is correct
8 Correct 2 ms 2948 KB Output is correct
9 Correct 2 ms 2940 KB Output is correct
10 Correct 2 ms 2892 KB Output is correct
11 Correct 2 ms 2892 KB Output is correct
12 Correct 2 ms 2948 KB Output is correct
13 Correct 3 ms 2928 KB Output is correct
14 Correct 2 ms 2892 KB Output is correct
15 Correct 3 ms 2892 KB Output is correct
16 Correct 2 ms 2892 KB Output is correct
17 Correct 82 ms 20140 KB Output is correct
18 Correct 64 ms 19908 KB Output is correct
19 Correct 68 ms 20296 KB Output is correct
20 Correct 71 ms 20208 KB Output is correct
21 Correct 75 ms 19908 KB Output is correct
22 Correct 80 ms 20268 KB Output is correct
23 Correct 63 ms 9976 KB Output is correct
24 Correct 76 ms 10692 KB Output is correct
25 Correct 77 ms 10884 KB Output is correct
26 Correct 3 ms 2876 KB Output is correct
27 Correct 21 ms 5608 KB Output is correct
28 Correct 80 ms 10756 KB Output is correct
29 Correct 79 ms 11076 KB Output is correct
30 Correct 72 ms 11452 KB Output is correct
31 Correct 83 ms 11720 KB Output is correct
32 Correct 67 ms 10304 KB Output is correct
33 Correct 73 ms 10804 KB Output is correct
34 Correct 2 ms 2892 KB Output is correct
35 Correct 2 ms 2892 KB Output is correct
36 Correct 2 ms 2892 KB Output is correct
37 Correct 3 ms 2892 KB Output is correct
38 Correct 3 ms 2948 KB Output is correct
39 Correct 2 ms 2892 KB Output is correct
40 Correct 3 ms 2892 KB Output is correct
41 Correct 2 ms 2892 KB Output is correct
42 Correct 2 ms 2892 KB Output is correct
43 Correct 3 ms 2892 KB Output is correct
44 Correct 2 ms 2892 KB Output is correct
45 Correct 73 ms 20104 KB Output is correct
46 Correct 68 ms 19908 KB Output is correct
47 Correct 73 ms 20240 KB Output is correct
48 Correct 66 ms 10044 KB Output is correct
49 Correct 68 ms 10652 KB Output is correct
50 Correct 73 ms 10820 KB Output is correct
51 Correct 2 ms 2892 KB Output is correct
52 Correct 23 ms 5592 KB Output is correct
53 Correct 71 ms 10816 KB Output is correct
54 Correct 80 ms 10948 KB Output is correct
55 Correct 75 ms 11420 KB Output is correct
56 Correct 77 ms 11708 KB Output is correct
57 Correct 67 ms 10344 KB Output is correct
58 Correct 71 ms 10844 KB Output is correct
59 Correct 22 ms 5592 KB Output is correct
60 Correct 62 ms 10144 KB Output is correct
61 Correct 69 ms 10732 KB Output is correct
62 Correct 68 ms 11016 KB Output is correct
63 Correct 69 ms 10920 KB Output is correct
64 Correct 68 ms 10980 KB Output is correct
65 Correct 59 ms 11460 KB Output is correct
66 Correct 61 ms 11380 KB Output is correct
67 Correct 59 ms 11396 KB Output is correct
68 Correct 54 ms 11304 KB Output is correct
69 Correct 60 ms 11280 KB Output is correct
70 Correct 55 ms 11256 KB Output is correct