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Submission #545051

# Submission time Handle Problem Language Result Execution time Memory
545051 2022-04-03T12:48:06 Z chonka Mergers (JOI19_mergers) C++
0 / 100
 103 ms 41916 KB 
#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;

// mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

#define MAXN 500007
#define LOG 20

int n , k ;
vector < int > v[ MAXN ] ;
int a[ MAXN ] ;
int lvl[ MAXN ] ;
int LCA[ MAXN ][ LOG ] ;
int st[ MAXN ] , tp ;
vector < int > col[ MAXN ] ;

void init ( int vertex , int prv ) {
    st[ vertex ] = ++ tp ;
    for ( int i = 1 ; i < LOG ; ++ i ) {
        LCA[ vertex ][ i ] = LCA[ LCA[ vertex ][ i - 1 ] ][ i - 1 ] ;
    }
    for ( auto x : v[ vertex ] ) {
        if ( x == prv ) { continue ; }
        lvl[ x ] = lvl[ vertex ] + 1 ;
        LCA[ x ][ 0 ] = vertex ;
        init ( x , vertex ) ;
    }
}

int ori[ MAXN ] ;

int get_lca ( int x , int y ) {
    for ( int i = LOG - 1 ; i >= 0 ; -- i ) {
        if ( lvl[ x ] - ( 1 << i ) >= lvl[ y ] ) {
            x = LCA[ x ][ i ] ;
        }
        if ( lvl[ y ] - ( 1 << i ) >= lvl[ x ] ) {
            y = LCA[ y ][ i ] ;
        }
    }
    for ( int i = LOG - 1 ; i >= 0 ; -- i ) {
        if ( LCA[ x ][ i ] != LCA[ y ][ i ] ) {
            x = LCA[ x ][ i ] ;
            y = LCA[ y ][ i ] ;
        }
    }
    if ( x != y ) { x = LCA[ x ][ 0 ] ; }
    return x ;
}

int dp[ MAXN ] ;
int bad[ MAXN ] ;

int dfs ( int vertex , int prv ) {
    int ret = lvl[ ori[ a[ vertex ] ] ] ;
    for ( auto x : v[ vertex ] ) {
        if ( x == prv ) { continue ; }
        int aux = dfs ( x , vertex ) ;
        ret = min ( ret , aux ) ;
        dp[ vertex ] += max ( bad[ x ] , dp[ x ] ) ;
    }
    if ( ret >= lvl[ vertex ] ) {
        bad[ vertex ] = 1 ;
    }
    return ret ;
}

void input ( ) {
    cin >> n >> k ;
    for ( int i = 1 ; i < n ; ++ i ) {
        int x , y ;
        cin >> x >> y ;
        v[ x ].push_back ( y ) ;
        v[ y ].push_back ( x ) ;
    }
    for ( int i = 1 ; i <= n ; ++ i ) {
        cin >> a[ i ] ;
        col[ a[ i ] ].push_back ( i ) ;
    }
}

void solve ( ) {
    init ( 1 , -1 ) ;
    auto cmp = [ & ] ( int x , int y ) {
        return ( st[ x ] < st[ y ] ) ;
    };
    for ( int i = 1 ; i <= k ; ++ i ) {
        sort ( col[ i ].begin ( ) , col[ i ].end ( ) , cmp ) ;
        ori[ i ] = get_lca ( col[ i ].front ( ) , col[ i ].back ( ) ) ;
    }
    dfs ( 1 , -1 ) ;
    cout << ( dp[ 1 ] + 1 ) / 2 << "\n" ;
}

int main ( ) {
    ios_base :: sync_with_stdio ( false ) ;
    cin.tie ( NULL ) ;
    int t = 1 ;
    // cin >> t ;
    while ( t -- ) {
        input ( ) ;
        solve ( ) ;
    }
    return 0 ;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23832 KB Output is correct
2 Correct 13 ms 23804 KB Output is correct
3 Correct 13 ms 23828 KB Output is correct
4 Correct 12 ms 23852 KB Output is correct
5 Correct 12 ms 23844 KB Output is correct
6 Correct 11 ms 23772 KB Output is correct
7 Correct 15 ms 23764 KB Output is correct
8 Correct 13 ms 23764 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 13 ms 23740 KB Output is correct
11 Correct 15 ms 23764 KB Output is correct
12 Correct 12 ms 23800 KB Output is correct
13 Correct 11 ms 23756 KB Output is correct
14 Correct 14 ms 23840 KB Output is correct
15 Correct 13 ms 23764 KB Output is correct
16 Incorrect 12 ms 23764 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23832 KB Output is correct
2 Correct 13 ms 23804 KB Output is correct
3 Correct 13 ms 23828 KB Output is correct
4 Correct 12 ms 23852 KB Output is correct
5 Correct 12 ms 23844 KB Output is correct
6 Correct 11 ms 23772 KB Output is correct
7 Correct 15 ms 23764 KB Output is correct
8 Correct 13 ms 23764 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 13 ms 23740 KB Output is correct
11 Correct 15 ms 23764 KB Output is correct
12 Correct 12 ms 23800 KB Output is correct
13 Correct 11 ms 23756 KB Output is correct
14 Correct 14 ms 23840 KB Output is correct
15 Correct 13 ms 23764 KB Output is correct
16 Incorrect 12 ms 23764 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23832 KB Output is correct
2 Correct 13 ms 23804 KB Output is correct
3 Correct 13 ms 23828 KB Output is correct
4 Correct 12 ms 23852 KB Output is correct
5 Correct 12 ms 23844 KB Output is correct
6 Correct 11 ms 23772 KB Output is correct
7 Correct 15 ms 23764 KB Output is correct
8 Correct 13 ms 23764 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 13 ms 23740 KB Output is correct
11 Correct 15 ms 23764 KB Output is correct
12 Correct 12 ms 23800 KB Output is correct
13 Correct 11 ms 23756 KB Output is correct
14 Correct 14 ms 23840 KB Output is correct
15 Correct 13 ms 23764 KB Output is correct
16 Incorrect 12 ms 23764 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 91 ms 38396 KB Output is correct
2 Incorrect 103 ms 41916 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23832 KB Output is correct
2 Correct 13 ms 23804 KB Output is correct
3 Correct 13 ms 23828 KB Output is correct
4 Correct 12 ms 23852 KB Output is correct
5 Correct 12 ms 23844 KB Output is correct
6 Correct 11 ms 23772 KB Output is correct
7 Correct 15 ms 23764 KB Output is correct
8 Correct 13 ms 23764 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 13 ms 23740 KB Output is correct
11 Correct 15 ms 23764 KB Output is correct
12 Correct 12 ms 23800 KB Output is correct
13 Correct 11 ms 23756 KB Output is correct
14 Correct 14 ms 23840 KB Output is correct
15 Correct 13 ms 23764 KB Output is correct
16 Incorrect 12 ms 23764 KB Output isn't correct
17 Halted 0 ms 0 KB -