oj.uz

Submission #957242

# Submission time Handle Problem Language Result Execution time Memory
957242 2024-04-03T09:45:50 Z LucaIlie Newspapers (CEOI21_newspapers) C++17
100 / 100
 150 ms 4440 KB 
#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 1e3;
int n;
int depth[MAX_N + 1], parent[MAX_N + 1], maxDepth[MAX_N + 1], lf[MAX_N + 1], sizee[MAX_N + 1];
vector<int> adj[MAX_N + 1];

int findCentroid( int u, int p ) {
    int c = 0, mx = 0;
    sizee[u] = 1;
    for ( int v: adj[u] ) {
        if ( v == p )
            continue;
        int x = findCentroid( v, u );
        if ( x != 0 )
            c = x;
        sizee[u] += sizee[v];
        mx = max( mx, sizee[v] );
    }
    mx = max( mx, n - sizee[u] );
    if ( mx <= n / 2 )
        c = u;
    return c;
}

bool ok = true;
void check( int u, int p ) {
    depth[u] = depth[p] + 1;
    maxDepth[u] = depth[u];
    int c = 0;
    for ( int v: adj[u] ) {
        if ( v == p )
            continue;
        check( v, u );
        maxDepth[u] = max( maxDepth[u], maxDepth[v] );
        if ( maxDepth[v] - depth[u] > 2 )
            c++;
    }
    if ( (depth[u] >= 3 && c >= 2) || (c >= 3) )
        ok = false;
}

bool isOnDiam[MAX_N + 1];
vector<int> diam;
int diamLen = 0, x = 0, y = 0, l = 0;
void dfs( int u, int p ) {
    int mx1 = -1, a = u, mx2 = -1, b = 0;

    parent[u] = p;
    for ( int v: adj[u] ) {
        if ( v == p )
            continue;

        dfs( v, u );
        if ( depth[v] > mx1 ) {
            mx2 = mx1;
            b = a;
            mx1 = depth[v];
            a = lf[v];
        } else if ( depth[v] > mx2 ) {
            mx2 = depth[v];
            b = lf[v];
        }
    }


    depth[u] = mx1 + 1;
    lf[u] = a;
    if ( mx1 + mx2 + 2 > diamLen ) {
        diamLen = mx1 + mx2 + 2;
        x = a;
        y = b;
        l = u;
    }
    //printf( "%d %d %d %d\n", u, mx1, mx2, depth[u] );
}

int main() {
    int m;

    cin >> n >> m;
    for ( int i = 0; i < m; i++ ) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back( v );
        adj[v].push_back( u );
    }

    if ( m != n - 1 ) {
        cout << "NO\n";
        return 0;
    }

    if ( n == 1 ) {
        cout << "YES\n1\n1\n";
        return 0;
    }
    if ( n <= 3 ) {
        cout << "YES\n2\n2 2\n";
        return 0;
    }

    int c = findCentroid( 1, 0 );
    check( c, 0 );

    if ( !ok ) {
        cout << "NO\n";
        return 0;
    }

    dfs( c, 0 );

    while ( x != l ) {
        diam.push_back( x );
        isOnDiam[x] = true;
        x = parent[x];
    }
    diam.push_back( l );
    isOnDiam[l] = true;

    vector<int> a;
    while ( y != l ) {
        a.push_back( y );
        isOnDiam[y] = true;
        y = parent[y];
    }
    reverse( a.begin(), a.end() );
    for ( int u: a )
        diam.push_back( u );

    vector<int> sol;
    for ( int i = 1; i <= diam.size() - 2; i++ ) {
        int v = diam[i];
        sol.push_back( v );
        for ( int u: adj[v] ) {
            if ( isOnDiam[u] || adj[u].size() == 1  )
                continue;
            sol.push_back( u );
            sol.push_back( v );
        }
    }
    reverse( diam.begin(), diam.end() );
    for ( int i = 1; i <= diam.size() - 2; i++ ) {
        int v = diam[i];
        sol.push_back( v );
        for ( int u: adj[v] ) {
            if ( isOnDiam[u] || adj[u].size() == 1 )
                continue;
            sol.push_back( u );
            sol.push_back( v );
        }
    }

    cout << "YES\n";
    cout << sol.size() << "\n";
    for ( int v: sol )
        cout << v << " ";

    return 0;
}

Compilation message

newspapers.cpp: In function 'int main()':
newspapers.cpp:134:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  134 |     for ( int i = 1; i <= diam.size() - 2; i++ ) {
      |                      ~~^~~~~~~~~~~~~~~~~~
newspapers.cpp:145:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  145 |     for ( int i = 1; i <= diam.size() - 2; i++ ) {
      |                      ~~^~~~~~~~~~~~~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 600 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 344 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 384 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 0 ms 360 KB Output is correct
28 Correct 0 ms 348 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 0 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 344 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 1 ms 348 KB Output is correct
36 Correct 1 ms 344 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 0 ms 348 KB Output is correct
45 Correct 0 ms 348 KB Output is correct
46 Correct 0 ms 344 KB Output is correct
47 Correct 0 ms 348 KB Output is correct
48 Correct 1 ms 348 KB Output is correct
49 Correct 0 ms 344 KB Output is correct
50 Correct 1 ms 344 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 0 ms 348 KB Output is correct
54 Correct 0 ms 348 KB Output is correct
55 Correct 0 ms 348 KB Output is correct
56 Correct 0 ms 348 KB Output is correct
57 Correct 0 ms 348 KB Output is correct
58 Correct 0 ms 348 KB Output is correct
59 Correct 0 ms 348 KB Output is correct
60 Correct 0 ms 348 KB Output is correct
61 Correct 0 ms 348 KB Output is correct
62 Correct 0 ms 348 KB Output is correct
63 Correct 1 ms 348 KB Output is correct
64 Correct 0 ms 348 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 344 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 1 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 600 KB Output is correct
19 Correct 1 ms 600 KB Output is correct
20 Correct 1 ms 600 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 600 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 344 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 384 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 0 ms 360 KB Output is correct
28 Correct 0 ms 348 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 0 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 344 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 1 ms 348 KB Output is correct
36 Correct 1 ms 344 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 0 ms 348 KB Output is correct
45 Correct 0 ms 348 KB Output is correct
46 Correct 0 ms 344 KB Output is correct
47 Correct 0 ms 348 KB Output is correct
48 Correct 1 ms 348 KB Output is correct
49 Correct 0 ms 344 KB Output is correct
50 Correct 1 ms 344 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 0 ms 348 KB Output is correct
54 Correct 0 ms 348 KB Output is correct
55 Correct 0 ms 348 KB Output is correct
56 Correct 0 ms 348 KB Output is correct
57 Correct 0 ms 348 KB Output is correct
58 Correct 0 ms 348 KB Output is correct
59 Correct 0 ms 348 KB Output is correct
60 Correct 0 ms 348 KB Output is correct
61 Correct 0 ms 348 KB Output is correct
62 Correct 0 ms 348 KB Output is correct
63 Correct 1 ms 348 KB Output is correct
64 Correct 0 ms 348 KB Output is correct
65 Correct 0 ms 344 KB Output is correct
66 Correct 0 ms 344 KB Output is correct
67 Correct 0 ms 344 KB Output is correct
68 Correct 1 ms 348 KB Output is correct
69 Correct 0 ms 500 KB Output is correct
70 Correct 0 ms 348 KB Output is correct
71 Correct 0 ms 348 KB Output is correct
72 Correct 0 ms 348 KB Output is correct
73 Correct 0 ms 348 KB Output is correct
74 Correct 0 ms 348 KB Output is correct
75 Correct 0 ms 348 KB Output is correct
76 Correct 0 ms 348 KB Output is correct
77 Correct 0 ms 348 KB Output is correct
78 Correct 0 ms 348 KB Output is correct
79 Correct 1 ms 348 KB Output is correct
80 Correct 1 ms 348 KB Output is correct
81 Correct 1 ms 348 KB Output is correct
82 Correct 1 ms 348 KB Output is correct
83 Correct 1 ms 348 KB Output is correct
84 Correct 1 ms 344 KB Output is correct
85 Correct 1 ms 348 KB Output is correct
86 Correct 1 ms 344 KB Output is correct
87 Correct 1 ms 344 KB Output is correct
88 Correct 1 ms 348 KB Output is correct
89 Correct 1 ms 348 KB Output is correct
90 Correct 1 ms 344 KB Output is correct
91 Correct 1 ms 348 KB Output is correct
92 Correct 1 ms 348 KB Output is correct
93 Correct 1 ms 348 KB Output is correct
94 Correct 1 ms 344 KB Output is correct
95 Correct 1 ms 344 KB Output is correct
96 Correct 2 ms 344 KB Output is correct
97 Correct 1 ms 348 KB Output is correct
98 Correct 1 ms 348 KB Output is correct
99 Correct 1 ms 600 KB Output is correct
100 Correct 1 ms 344 KB Output is correct
101 Correct 1 ms 348 KB Output is correct
102 Correct 1 ms 348 KB Output is correct
103 Correct 1 ms 348 KB Output is correct
104 Correct 1 ms 348 KB Output is correct
105 Correct 1 ms 348 KB Output is correct
106 Correct 1 ms 348 KB Output is correct
107 Correct 1 ms 348 KB Output is correct
108 Correct 1 ms 348 KB Output is correct
109 Correct 1 ms 348 KB Output is correct
110 Correct 1 ms 348 KB Output is correct
111 Correct 1 ms 348 KB Output is correct
112 Correct 1 ms 348 KB Output is correct
113 Correct 1 ms 348 KB Output is correct
114 Correct 1 ms 348 KB Output is correct
115 Correct 1 ms 344 KB Output is correct
116 Correct 1 ms 348 KB Output is correct
117 Correct 1 ms 348 KB Output is correct
118 Correct 1 ms 344 KB Output is correct
119 Correct 1 ms 344 KB Output is correct
120 Correct 1 ms 348 KB Output is correct
121 Correct 1 ms 348 KB Output is correct
122 Correct 1 ms 348 KB Output is correct
123 Correct 1 ms 348 KB Output is correct
124 Correct 1 ms 348 KB Output is correct
125 Correct 1 ms 348 KB Output is correct
126 Correct 1 ms 348 KB Output is correct
127 Correct 1 ms 348 KB Output is correct
128 Correct 1 ms 348 KB Output is correct
129 Correct 1 ms 348 KB Output is correct
130 Correct 1 ms 348 KB Output is correct
131 Correct 1 ms 348 KB Output is correct
132 Correct 1 ms 348 KB Output is correct
133 Correct 1 ms 348 KB Output is correct
134 Correct 28 ms 1428 KB Output is correct
135 Correct 24 ms 1372 KB Output is correct
136 Correct 64 ms 3920 KB Output is correct
137 Correct 41 ms 2388 KB Output is correct
138 Correct 71 ms 2900 KB Output is correct
139 Correct 130 ms 4436 KB Output is correct
140 Correct 18 ms 1116 KB Output is correct
141 Correct 7 ms 604 KB Output is correct
142 Correct 121 ms 4432 KB Output is correct
143 Correct 150 ms 4440 KB Output is correct
144 Correct 1 ms 760 KB Output is correct
145 Correct 1 ms 600 KB Output is correct