oj.uz

Submission #339252

# Submission time Handle Problem Language Result Execution time Memory
339252 2020-12-25T00:41:34 Z KWang31 Mergers (JOI19_mergers) Java 11
70 / 100
 3000 ms 135720 KB 
import java.io.*; import java.util.*;
public class mergers{
  static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        
    } 
    
    static int MOD=998244353;
    
    static int[] par,dep;
    static int[] skip;
    public static void main(String[] args){
        FastReader br=new FastReader();
        int N=br.nextInt(); int M=br.nextInt();
        ArrayList<Integer> states[]=new ArrayList[M]; for(int i=0;i<M;i++){states[i]=new ArrayList<>();}
        ArrayList<Integer> adj[]=new ArrayList[N]; for(int i=0;i<N;i++){adj[i]=new ArrayList<>();}
        int a,b;
        for (int i = 0; i < N-1; i++) {
            a=br.nextInt()-1; b=br.nextInt()-1; adj[a].add(b); adj[b].add(a);
        }
        for (int i = 0; i < N; i++) {
            a=br.nextInt()-1; states[a].add(i);
        }
        par=new int[N]; dep=new int[N]; dfs(adj,-1,0);
        
        skip=new int[N];//Skipping: avoiding repeated merging
        for (int i = 0; i < N; i++) {
            skip[i]=i;
        }
        int u;
        for (int i = 0; i < M; i++) {
            if(states[i].isEmpty())continue;
            u=states[i].get(0);
            for (int j = 1; j < states[i].size(); j++) {
                a=u; b=states[i].get(j);
                
                while(a!=b){
                    if(dep[a]>=dep[b]){
                        skip[a]=find(par[a]); a=skip[a]; 
                    }else{
                        skip[b]=find(par[b]); b=skip[b]; 
                    }
                }
                //For each a, we have merged a with its 1st, .., kth ancestor.
                //They belong to the same state
            }
        }
        //In the end, all vertices of the same state have the same skip
        //Therefore, after merging, if two vertices don't have some skip, they are not in the same state
        int[] deg=new int[N];
        
        for (int i = 0; i < N; i++) {
            a=find(i);
            for (int j : adj[i]) {
                if(a!=find(j)){
                    //Notice in the compressed form, there is only one leader for each state, namely j
                    //If i is adjacent to two vertices with same find, i must have that find too
                    deg[a]++;
                }
            }
        }
        //System.out.println(Arrays.toString(deg));
        int ans=0;
        for (int i = 0; i < N; i++) {
            if(deg[i]==1)ans++;
        }
        System.out.println((ans+1)/2);
        //If a state is a leaf, there exist exactly one 
    }
    
    public static int find(int x){
        if(skip[x]==x)return x;
        skip[x]=find(skip[x]); return skip[x];
    }
    public static void dfs(ArrayList<Integer>[] adj, int p, int v){
        for (int c : adj[v]) {
            if(c==p)continue;
            dep[c]=dep[v]+1; par[c]=v; dfs(adj,v,c);
        }
    }
}
//Debugging:
//Are you sure your algorithm is correct?
//Bounds: long
//Special cases: n=0,1?
//Make sure you remove your debugging code before you submit!

Compilation message

Note: mergers.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8428 KB Output is correct
2 Correct 77 ms 8540 KB Output is correct
3 Correct 76 ms 8556 KB Output is correct
4 Correct 74 ms 8428 KB Output is correct
5 Correct 70 ms 8556 KB Output is correct
6 Correct 78 ms 8656 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 77 ms 8668 KB Output is correct
9 Correct 71 ms 8556 KB Output is correct
10 Correct 70 ms 8556 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 75 ms 8556 KB Output is correct
13 Correct 72 ms 8448 KB Output is correct
14 Correct 79 ms 8664 KB Output is correct
15 Correct 78 ms 8556 KB Output is correct
16 Correct 72 ms 8556 KB Output is correct
17 Correct 72 ms 8460 KB Output is correct
18 Correct 78 ms 8560 KB Output is correct
19 Correct 71 ms 8684 KB Output is correct
20 Correct 72 ms 8664 KB Output is correct
21 Correct 77 ms 8596 KB Output is correct
22 Correct 76 ms 8556 KB Output is correct
23 Correct 70 ms 8556 KB Output is correct
24 Correct 74 ms 8684 KB Output is correct

Subtask #2
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8428 KB Output is correct
2 Correct 77 ms 8540 KB Output is correct
3 Correct 76 ms 8556 KB Output is correct
4 Correct 74 ms 8428 KB Output is correct
5 Correct 70 ms 8556 KB Output is correct
6 Correct 78 ms 8656 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 77 ms 8668 KB Output is correct
9 Correct 71 ms 8556 KB Output is correct
10 Correct 70 ms 8556 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 75 ms 8556 KB Output is correct
13 Correct 72 ms 8448 KB Output is correct
14 Correct 79 ms 8664 KB Output is correct
15 Correct 78 ms 8556 KB Output is correct
16 Correct 72 ms 8556 KB Output is correct
17 Correct 72 ms 8460 KB Output is correct
18 Correct 78 ms 8560 KB Output is correct
19 Correct 71 ms 8684 KB Output is correct
20 Correct 72 ms 8664 KB Output is correct
21 Correct 77 ms 8596 KB Output is correct
22 Correct 76 ms 8556 KB Output is correct
23 Correct 70 ms 8556 KB Output is correct
24 Correct 74 ms 8684 KB Output is correct
25 Correct 74 ms 8556 KB Output is correct
26 Correct 288 ms 14580 KB Output is correct
27 Correct 289 ms 14672 KB Output is correct
28 Correct 289 ms 14816 KB Output is correct
29 Correct 289 ms 14676 KB Output is correct
30 Correct 284 ms 14544 KB Output is correct
31 Correct 75 ms 8668 KB Output is correct
32 Correct 301 ms 15136 KB Output is correct
33 Correct 79 ms 8556 KB Output is correct
34 Correct 281 ms 14556 KB Output is correct
35 Correct 287 ms 14652 KB Output is correct
36 Correct 283 ms 14432 KB Output is correct
37 Correct 286 ms 14552 KB Output is correct
38 Correct 81 ms 8668 KB Output is correct
39 Correct 316 ms 14580 KB Output is correct
40 Correct 334 ms 14560 KB Output is correct
41 Correct 282 ms 14432 KB Output is correct
42 Correct 287 ms 14432 KB Output is correct
43 Correct 285 ms 14928 KB Output is correct
44 Correct 76 ms 8428 KB Output is correct
45 Correct 340 ms 14844 KB Output is correct
46 Correct 337 ms 14444 KB Output is correct
47 Correct 76 ms 8556 KB Output is correct
48 Correct 288 ms 14532 KB Output is correct
49 Correct 292 ms 14636 KB Output is correct
50 Correct 291 ms 14928 KB Output is correct
51 Correct 289 ms 14560 KB Output is correct
52 Correct 286 ms 14384 KB Output is correct
53 Correct 295 ms 14588 KB Output is correct
54 Correct 286 ms 14560 KB Output is correct

Subtask #3
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8428 KB Output is correct
2 Correct 77 ms 8540 KB Output is correct
3 Correct 76 ms 8556 KB Output is correct
4 Correct 74 ms 8428 KB Output is correct
5 Correct 70 ms 8556 KB Output is correct
6 Correct 78 ms 8656 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 77 ms 8668 KB Output is correct
9 Correct 71 ms 8556 KB Output is correct
10 Correct 70 ms 8556 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 75 ms 8556 KB Output is correct
13 Correct 72 ms 8448 KB Output is correct
14 Correct 79 ms 8664 KB Output is correct
15 Correct 78 ms 8556 KB Output is correct
16 Correct 72 ms 8556 KB Output is correct
17 Correct 72 ms 8460 KB Output is correct
18 Correct 78 ms 8560 KB Output is correct
19 Correct 71 ms 8684 KB Output is correct
20 Correct 72 ms 8664 KB Output is correct
21 Correct 77 ms 8596 KB Output is correct
22 Correct 76 ms 8556 KB Output is correct
23 Correct 70 ms 8556 KB Output is correct
24 Correct 74 ms 8684 KB Output is correct
25 Correct 76 ms 8556 KB Output is correct
26 Correct 700 ms 35216 KB Output is correct
27 Correct 710 ms 35428 KB Output is correct
28 Correct 282 ms 14672 KB Output is correct
29 Correct 73 ms 8556 KB Output is correct
30 Correct 73 ms 8556 KB Output is correct
31 Correct 720 ms 35304 KB Output is correct
32 Correct 280 ms 14556 KB Output is correct
33 Correct 788 ms 40660 KB Output is correct
34 Correct 769 ms 35268 KB Output is correct
35 Correct 285 ms 14432 KB Output is correct
36 Correct 782 ms 36268 KB Output is correct
37 Correct 332 ms 14800 KB Output is correct
38 Correct 281 ms 14432 KB Output is correct
39 Correct 673 ms 35532 KB Output is correct
40 Correct 287 ms 14836 KB Output is correct
41 Correct 706 ms 35032 KB Output is correct
42 Correct 1004 ms 37696 KB Output is correct
43 Correct 78 ms 8556 KB Output is correct
44 Correct 735 ms 40496 KB Output is correct
45 Correct 758 ms 38684 KB Output is correct
46 Correct 284 ms 14436 KB Output is correct
47 Correct 282 ms 14560 KB Output is correct

Subtask #4
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 704 ms 34872 KB Output is correct
2 Correct 750 ms 48104 KB Output is correct
3 Correct 292 ms 14560 KB Output is correct
4 Correct 291 ms 14392 KB Output is correct
5 Correct 73 ms 8556 KB Output is correct
6 Correct 77 ms 8576 KB Output is correct
7 Correct 280 ms 14556 KB Output is correct
8 Correct 769 ms 37368 KB Output is correct
9 Correct 285 ms 14432 KB Output is correct
10 Correct 732 ms 35028 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 726 ms 35192 KB Output is correct
13 Correct 755 ms 37520 KB Output is correct
14 Correct 822 ms 41636 KB Output is correct
15 Correct 669 ms 35580 KB Output is correct
16 Correct 289 ms 14560 KB Output is correct
17 Correct 76 ms 8556 KB Output is correct
18 Correct 768 ms 47328 KB Output is correct
19 Correct 1231 ms 50476 KB Output is correct
20 Correct 339 ms 14688 KB Output is correct
21 Correct 78 ms 8668 KB Output is correct
22 Correct 768 ms 39968 KB Output is correct
23 Correct 287 ms 14708 KB Output is correct
24 Correct 731 ms 35668 KB Output is correct
25 Correct 768 ms 44048 KB Output is correct
26 Correct 293 ms 14616 KB Output is correct
27 Correct 289 ms 14688 KB Output is correct
28 Correct 289 ms 14556 KB Output is correct
29 Correct 284 ms 14688 KB Output is correct
30 Correct 287 ms 14580 KB Output is correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8428 KB Output is correct
2 Correct 77 ms 8540 KB Output is correct
3 Correct 76 ms 8556 KB Output is correct
4 Correct 74 ms 8428 KB Output is correct
5 Correct 70 ms 8556 KB Output is correct
6 Correct 78 ms 8656 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 77 ms 8668 KB Output is correct
9 Correct 71 ms 8556 KB Output is correct
10 Correct 70 ms 8556 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 75 ms 8556 KB Output is correct
13 Correct 72 ms 8448 KB Output is correct
14 Correct 79 ms 8664 KB Output is correct
15 Correct 78 ms 8556 KB Output is correct
16 Correct 72 ms 8556 KB Output is correct
17 Correct 72 ms 8460 KB Output is correct
18 Correct 78 ms 8560 KB Output is correct
19 Correct 71 ms 8684 KB Output is correct
20 Correct 72 ms 8664 KB Output is correct
21 Correct 77 ms 8596 KB Output is correct
22 Correct 76 ms 8556 KB Output is correct
23 Correct 70 ms 8556 KB Output is correct
24 Correct 74 ms 8684 KB Output is correct
25 Correct 74 ms 8556 KB Output is correct
26 Correct 288 ms 14580 KB Output is correct
27 Correct 289 ms 14672 KB Output is correct
28 Correct 289 ms 14816 KB Output is correct
29 Correct 289 ms 14676 KB Output is correct
30 Correct 284 ms 14544 KB Output is correct
31 Correct 75 ms 8668 KB Output is correct
32 Correct 301 ms 15136 KB Output is correct
33 Correct 79 ms 8556 KB Output is correct
34 Correct 281 ms 14556 KB Output is correct
35 Correct 287 ms 14652 KB Output is correct
36 Correct 283 ms 14432 KB Output is correct
37 Correct 286 ms 14552 KB Output is correct
38 Correct 81 ms 8668 KB Output is correct
39 Correct 316 ms 14580 KB Output is correct
40 Correct 334 ms 14560 KB Output is correct
41 Correct 282 ms 14432 KB Output is correct
42 Correct 287 ms 14432 KB Output is correct
43 Correct 285 ms 14928 KB Output is correct
44 Correct 76 ms 8428 KB Output is correct
45 Correct 340 ms 14844 KB Output is correct
46 Correct 337 ms 14444 KB Output is correct
47 Correct 76 ms 8556 KB Output is correct
48 Correct 288 ms 14532 KB Output is correct
49 Correct 292 ms 14636 KB Output is correct
50 Correct 291 ms 14928 KB Output is correct
51 Correct 289 ms 14560 KB Output is correct
52 Correct 286 ms 14384 KB Output is correct
53 Correct 295 ms 14588 KB Output is correct
54 Correct 286 ms 14560 KB Output is correct
55 Correct 76 ms 8556 KB Output is correct
56 Correct 700 ms 35216 KB Output is correct
57 Correct 710 ms 35428 KB Output is correct
58 Correct 282 ms 14672 KB Output is correct
59 Correct 73 ms 8556 KB Output is correct
60 Correct 73 ms 8556 KB Output is correct
61 Correct 720 ms 35304 KB Output is correct
62 Correct 280 ms 14556 KB Output is correct
63 Correct 788 ms 40660 KB Output is correct
64 Correct 769 ms 35268 KB Output is correct
65 Correct 285 ms 14432 KB Output is correct
66 Correct 782 ms 36268 KB Output is correct
67 Correct 332 ms 14800 KB Output is correct
68 Correct 281 ms 14432 KB Output is correct
69 Correct 673 ms 35532 KB Output is correct
70 Correct 287 ms 14836 KB Output is correct
71 Correct 706 ms 35032 KB Output is correct
72 Correct 1004 ms 37696 KB Output is correct
73 Correct 78 ms 8556 KB Output is correct
74 Correct 735 ms 40496 KB Output is correct
75 Correct 758 ms 38684 KB Output is correct
76 Correct 284 ms 14436 KB Output is correct
77 Correct 282 ms 14560 KB Output is correct
78 Correct 704 ms 34872 KB Output is correct
79 Correct 750 ms 48104 KB Output is correct
80 Correct 292 ms 14560 KB Output is correct
81 Correct 291 ms 14392 KB Output is correct
82 Correct 73 ms 8556 KB Output is correct
83 Correct 77 ms 8576 KB Output is correct
84 Correct 280 ms 14556 KB Output is correct
85 Correct 769 ms 37368 KB Output is correct
86 Correct 285 ms 14432 KB Output is correct
87 Correct 732 ms 35028 KB Output is correct
88 Correct 76 ms 8556 KB Output is correct
89 Correct 726 ms 35192 KB Output is correct
90 Correct 755 ms 37520 KB Output is correct
91 Correct 822 ms 41636 KB Output is correct
92 Correct 669 ms 35580 KB Output is correct
93 Correct 289 ms 14560 KB Output is correct
94 Correct 76 ms 8556 KB Output is correct
95 Correct 768 ms 47328 KB Output is correct
96 Correct 1231 ms 50476 KB Output is correct
97 Correct 339 ms 14688 KB Output is correct
98 Correct 78 ms 8668 KB Output is correct
99 Correct 768 ms 39968 KB Output is correct
100 Correct 287 ms 14708 KB Output is correct
101 Correct 731 ms 35668 KB Output is correct
102 Correct 768 ms 44048 KB Output is correct
103 Correct 293 ms 14616 KB Output is correct
104 Correct 289 ms 14688 KB Output is correct
105 Correct 289 ms 14556 KB Output is correct
106 Correct 284 ms 14688 KB Output is correct
107 Correct 287 ms 14580 KB Output is correct
108 Correct 2036 ms 131956 KB Output is correct
109 Correct 2171 ms 135720 KB Output is correct
110 Execution timed out 3097 ms 132892 KB Time limit exceeded
111 Halted 0 ms 0 KB -