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Submission #680437

# Submission time Handle Problem Language Result Execution time Memory
680437 2023-01-10T21:00:49 Z qwerasdfzxcl Wells (CEOI21_wells) C++17
0 / 100
 98 ms 72260 KB 
#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
int dist[10010][10010], vcnt, n, k;
vector<int> adj[1501500], G[1501500], st;
vector<vector<int>> path;

void dfs(int s, int pa = -1){
    st.push_back(s);
    if ((int)st.size()==k) path.push_back(st);
    dist[st[0]][s] = (int)st.size() - 1;

    for (auto &v:adj[s]) if (v!=pa){
        dfs(v, s);
    }

    st.pop_back();
}

int col[1501500];
bool simulate(int s, bool flag = 0){
    vector<int> q = {s};
    fill(col+1, col+n+1, 0);
    col[s] = 1;

    while(!q.empty()){
        int v = q.back(); q.pop_back();
        for (int i=1;i<=n;i++) if (dist[v][i]==k && !col[i]){
            col[i] = 1;
            q.push_back(i);
        }
    }

    vector<vector<int>> npath;
    for (auto &p:path){
        int cnt = 0;
        for (auto &x:p) if (col[x]) cnt++;
        if (cnt>1) return 0;

        if (cnt==0) npath.push_back(p);
    }
    if (flag) swap(path, npath);
    return 1;
}

int main(){
    scanf("%d %d", &n, &k);
    for (int i=1;i<=n-1;i++){
        int x, y;
        scanf("%d %d", &x, &y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    for (int i=1;i<=n;i++){
        dfs(i);
    }

    for (int i=1;i<=n;i++) if (simulate(i)){
        printf("YES\n0\n");
        return 0;
    }
    for (int i=1;i<=n;i++) if (simulate(i, 1) && path.empty()){
        printf("YES\n0\n");
        return 0;
    }
    printf("NO\n0\n");
    return 0;
}

Compilation message

wells.cpp: In function 'int main()':
wells.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
wells.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 30.0

# Verdict Execution time Memory Grader output
1 Partially correct 46 ms 70744 KB Output is partially correct
2 Partially correct 39 ms 71828 KB Output is partially correct
3 Partially correct 35 ms 71784 KB Output is partially correct
4 Partially correct 34 ms 71812 KB Output is partially correct
5 Partially correct 33 ms 71892 KB Output is partially correct
6 Partially correct 46 ms 71784 KB Output is partially correct
7 Correct 67 ms 71852 KB Output is correct
8 Partially correct 36 ms 71776 KB Output is partially correct
9 Partially correct 41 ms 71884 KB Output is partially correct
10 Correct 98 ms 71900 KB Output is correct
11 Partially correct 35 ms 71944 KB Output is partially correct
12 Partially correct 34 ms 71800 KB Output is partially correct
13 Partially correct 37 ms 71836 KB Output is partially correct
14 Partially correct 42 ms 71908 KB Output is partially correct
15 Partially correct 34 ms 71856 KB Output is partially correct
16 Partially correct 34 ms 71792 KB Output is partially correct
17 Partially correct 37 ms 71892 KB Output is partially correct
18 Partially correct 46 ms 71928 KB Output is partially correct
19 Partially correct 36 ms 71740 KB Output is partially correct
20 Incorrect 41 ms 72260 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #2
0.0 / 20.0

# Verdict Execution time Memory Grader output
1 Partially correct 46 ms 70744 KB Output is partially correct
2 Partially correct 39 ms 71828 KB Output is partially correct
3 Partially correct 35 ms 71784 KB Output is partially correct
4 Partially correct 34 ms 71812 KB Output is partially correct
5 Partially correct 33 ms 71892 KB Output is partially correct
6 Partially correct 46 ms 71784 KB Output is partially correct
7 Correct 67 ms 71852 KB Output is correct
8 Partially correct 36 ms 71776 KB Output is partially correct
9 Partially correct 41 ms 71884 KB Output is partially correct
10 Correct 98 ms 71900 KB Output is correct
11 Partially correct 35 ms 71944 KB Output is partially correct
12 Partially correct 34 ms 71800 KB Output is partially correct
13 Partially correct 37 ms 71836 KB Output is partially correct
14 Partially correct 42 ms 71908 KB Output is partially correct
15 Partially correct 34 ms 71856 KB Output is partially correct
16 Partially correct 34 ms 71792 KB Output is partially correct
17 Partially correct 37 ms 71892 KB Output is partially correct
18 Partially correct 46 ms 71928 KB Output is partially correct
19 Partially correct 36 ms 71740 KB Output is partially correct
20 Incorrect 41 ms 72260 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #3
0.0 / 20.0

# Verdict Execution time Memory Grader output
1 Partially correct 46 ms 70744 KB Output is partially correct
2 Partially correct 39 ms 71828 KB Output is partially correct
3 Partially correct 35 ms 71784 KB Output is partially correct
4 Partially correct 34 ms 71812 KB Output is partially correct
5 Partially correct 33 ms 71892 KB Output is partially correct
6 Partially correct 46 ms 71784 KB Output is partially correct
7 Correct 67 ms 71852 KB Output is correct
8 Partially correct 36 ms 71776 KB Output is partially correct
9 Partially correct 41 ms 71884 KB Output is partially correct
10 Correct 98 ms 71900 KB Output is correct
11 Partially correct 35 ms 71944 KB Output is partially correct
12 Partially correct 34 ms 71800 KB Output is partially correct
13 Partially correct 37 ms 71836 KB Output is partially correct
14 Partially correct 42 ms 71908 KB Output is partially correct
15 Partially correct 34 ms 71856 KB Output is partially correct
16 Partially correct 34 ms 71792 KB Output is partially correct
17 Partially correct 37 ms 71892 KB Output is partially correct
18 Partially correct 46 ms 71928 KB Output is partially correct
19 Partially correct 36 ms 71740 KB Output is partially correct
20 Incorrect 41 ms 72260 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #4
0.0 / 30.0

# Verdict Execution time Memory Grader output
1 Partially correct 46 ms 70744 KB Output is partially correct
2 Partially correct 39 ms 71828 KB Output is partially correct
3 Partially correct 35 ms 71784 KB Output is partially correct
4 Partially correct 34 ms 71812 KB Output is partially correct
5 Partially correct 33 ms 71892 KB Output is partially correct
6 Partially correct 46 ms 71784 KB Output is partially correct
7 Correct 67 ms 71852 KB Output is correct
8 Partially correct 36 ms 71776 KB Output is partially correct
9 Partially correct 41 ms 71884 KB Output is partially correct
10 Correct 98 ms 71900 KB Output is correct
11 Partially correct 35 ms 71944 KB Output is partially correct
12 Partially correct 34 ms 71800 KB Output is partially correct
13 Partially correct 37 ms 71836 KB Output is partially correct
14 Partially correct 42 ms 71908 KB Output is partially correct
15 Partially correct 34 ms 71856 KB Output is partially correct
16 Partially correct 34 ms 71792 KB Output is partially correct
17 Partially correct 37 ms 71892 KB Output is partially correct
18 Partially correct 46 ms 71928 KB Output is partially correct
19 Partially correct 36 ms 71740 KB Output is partially correct
20 Incorrect 41 ms 72260 KB Output isn't correct
21 Halted 0 ms 0 KB -