oj.uz

Submission #339250

# Submission time Handle Problem Language Result Execution time Memory
339250 2020-12-25T00:36:54 Z KWang31 Mergers (JOI19_mergers) Java 11
70 / 100
 3000 ms 136020 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;
        }
        
        for (int i = 0; i < M; i++) {
            if(states[i].isEmpty())continue;
            
            for (int j = 0; j < states[i].size()-1; j++) {
                a=states[i].get(j); b=states[i].get(j+1);
                
                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 8556 KB Output is correct
2 Correct 77 ms 8556 KB Output is correct
3 Correct 78 ms 8812 KB Output is correct
4 Correct 71 ms 8556 KB Output is correct
5 Correct 71 ms 8556 KB Output is correct
6 Correct 77 ms 8556 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 78 ms 8660 KB Output is correct
9 Correct 75 ms 8556 KB Output is correct
10 Correct 70 ms 8428 KB Output is correct
11 Correct 77 ms 8540 KB Output is correct
12 Correct 76 ms 8472 KB Output is correct
13 Correct 71 ms 8488 KB Output is correct
14 Correct 77 ms 8556 KB Output is correct
15 Correct 79 ms 8608 KB Output is correct
16 Correct 73 ms 8556 KB Output is correct
17 Correct 71 ms 8556 KB Output is correct
18 Correct 75 ms 8556 KB Output is correct
19 Correct 71 ms 8528 KB Output is correct
20 Correct 72 ms 8540 KB Output is correct
21 Correct 78 ms 8556 KB Output is correct
22 Correct 78 ms 8536 KB Output is correct
23 Correct 73 ms 8376 KB Output is correct
24 Correct 75 ms 8556 KB Output is correct

Subtask #2
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8556 KB Output is correct
2 Correct 77 ms 8556 KB Output is correct
3 Correct 78 ms 8812 KB Output is correct
4 Correct 71 ms 8556 KB Output is correct
5 Correct 71 ms 8556 KB Output is correct
6 Correct 77 ms 8556 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 78 ms 8660 KB Output is correct
9 Correct 75 ms 8556 KB Output is correct
10 Correct 70 ms 8428 KB Output is correct
11 Correct 77 ms 8540 KB Output is correct
12 Correct 76 ms 8472 KB Output is correct
13 Correct 71 ms 8488 KB Output is correct
14 Correct 77 ms 8556 KB Output is correct
15 Correct 79 ms 8608 KB Output is correct
16 Correct 73 ms 8556 KB Output is correct
17 Correct 71 ms 8556 KB Output is correct
18 Correct 75 ms 8556 KB Output is correct
19 Correct 71 ms 8528 KB Output is correct
20 Correct 72 ms 8540 KB Output is correct
21 Correct 78 ms 8556 KB Output is correct
22 Correct 78 ms 8536 KB Output is correct
23 Correct 73 ms 8376 KB Output is correct
24 Correct 75 ms 8556 KB Output is correct
25 Correct 73 ms 8556 KB Output is correct
26 Correct 291 ms 14588 KB Output is correct
27 Correct 286 ms 14432 KB Output is correct
28 Correct 287 ms 14944 KB Output is correct
29 Correct 283 ms 14688 KB Output is correct
30 Correct 287 ms 14540 KB Output is correct
31 Correct 75 ms 8556 KB Output is correct
32 Correct 290 ms 14816 KB Output is correct
33 Correct 74 ms 8552 KB Output is correct
34 Correct 280 ms 14556 KB Output is correct
35 Correct 289 ms 14816 KB Output is correct
36 Correct 290 ms 14432 KB Output is correct
37 Correct 292 ms 14644 KB Output is correct
38 Correct 77 ms 8540 KB Output is correct
39 Correct 320 ms 14688 KB Output is correct
40 Correct 334 ms 14560 KB Output is correct
41 Correct 286 ms 14432 KB Output is correct
42 Correct 285 ms 14816 KB Output is correct
43 Correct 285 ms 15080 KB Output is correct
44 Correct 76 ms 8556 KB Output is correct
45 Correct 336 ms 14688 KB Output is correct
46 Correct 336 ms 14688 KB Output is correct
47 Correct 76 ms 8684 KB Output is correct
48 Correct 293 ms 14736 KB Output is correct
49 Correct 288 ms 14688 KB Output is correct
50 Correct 287 ms 14944 KB Output is correct
51 Correct 290 ms 14560 KB Output is correct
52 Correct 291 ms 14432 KB Output is correct
53 Correct 289 ms 14612 KB Output is correct
54 Correct 286 ms 14544 KB Output is correct

Subtask #3
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8556 KB Output is correct
2 Correct 77 ms 8556 KB Output is correct
3 Correct 78 ms 8812 KB Output is correct
4 Correct 71 ms 8556 KB Output is correct
5 Correct 71 ms 8556 KB Output is correct
6 Correct 77 ms 8556 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 78 ms 8660 KB Output is correct
9 Correct 75 ms 8556 KB Output is correct
10 Correct 70 ms 8428 KB Output is correct
11 Correct 77 ms 8540 KB Output is correct
12 Correct 76 ms 8472 KB Output is correct
13 Correct 71 ms 8488 KB Output is correct
14 Correct 77 ms 8556 KB Output is correct
15 Correct 79 ms 8608 KB Output is correct
16 Correct 73 ms 8556 KB Output is correct
17 Correct 71 ms 8556 KB Output is correct
18 Correct 75 ms 8556 KB Output is correct
19 Correct 71 ms 8528 KB Output is correct
20 Correct 72 ms 8540 KB Output is correct
21 Correct 78 ms 8556 KB Output is correct
22 Correct 78 ms 8536 KB Output is correct
23 Correct 73 ms 8376 KB Output is correct
24 Correct 75 ms 8556 KB Output is correct
25 Correct 74 ms 8668 KB Output is correct
26 Correct 695 ms 35120 KB Output is correct
27 Correct 714 ms 35412 KB Output is correct
28 Correct 286 ms 14560 KB Output is correct
29 Correct 74 ms 8428 KB Output is correct
30 Correct 75 ms 8556 KB Output is correct
31 Correct 732 ms 35276 KB Output is correct
32 Correct 285 ms 14676 KB Output is correct
33 Correct 788 ms 40500 KB Output is correct
34 Correct 779 ms 35124 KB Output is correct
35 Correct 287 ms 14544 KB Output is correct
36 Correct 792 ms 36560 KB Output is correct
37 Correct 334 ms 14560 KB Output is correct
38 Correct 287 ms 14272 KB Output is correct
39 Correct 682 ms 35392 KB Output is correct
40 Correct 290 ms 14928 KB Output is correct
41 Correct 724 ms 35144 KB Output is correct
42 Correct 999 ms 37672 KB Output is correct
43 Correct 75 ms 8556 KB Output is correct
44 Correct 736 ms 40532 KB Output is correct
45 Correct 772 ms 38688 KB Output is correct
46 Correct 287 ms 14432 KB Output is correct
47 Correct 284 ms 14560 KB Output is correct

Subtask #4
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 699 ms 34852 KB Output is correct
2 Correct 741 ms 41380 KB Output is correct
3 Correct 288 ms 14672 KB Output is correct
4 Correct 309 ms 14632 KB Output is correct
5 Correct 73 ms 8556 KB Output is correct
6 Correct 76 ms 8684 KB Output is correct
7 Correct 287 ms 14684 KB Output is correct
8 Correct 760 ms 37136 KB Output is correct
9 Correct 301 ms 14632 KB Output is correct
10 Correct 734 ms 34920 KB Output is correct
11 Correct 76 ms 8556 KB Output is correct
12 Correct 726 ms 35300 KB Output is correct
13 Correct 754 ms 37376 KB Output is correct
14 Correct 810 ms 41604 KB Output is correct
15 Correct 672 ms 35772 KB Output is correct
16 Correct 293 ms 14560 KB Output is correct
17 Correct 81 ms 8684 KB Output is correct
18 Correct 751 ms 47072 KB Output is correct
19 Correct 1204 ms 50576 KB Output is correct
20 Correct 337 ms 14688 KB Output is correct
21 Correct 77 ms 8680 KB Output is correct
22 Correct 758 ms 39976 KB Output is correct
23 Correct 285 ms 14560 KB Output is correct
24 Correct 731 ms 35924 KB Output is correct
25 Correct 751 ms 44036 KB Output is correct
26 Correct 294 ms 14852 KB Output is correct
27 Correct 286 ms 14816 KB Output is correct
28 Correct 283 ms 14448 KB Output is correct
29 Correct 297 ms 14492 KB Output is correct
30 Correct 288 ms 14560 KB Output is correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 8556 KB Output is correct
2 Correct 77 ms 8556 KB Output is correct
3 Correct 78 ms 8812 KB Output is correct
4 Correct 71 ms 8556 KB Output is correct
5 Correct 71 ms 8556 KB Output is correct
6 Correct 77 ms 8556 KB Output is correct
7 Correct 71 ms 8556 KB Output is correct
8 Correct 78 ms 8660 KB Output is correct
9 Correct 75 ms 8556 KB Output is correct
10 Correct 70 ms 8428 KB Output is correct
11 Correct 77 ms 8540 KB Output is correct
12 Correct 76 ms 8472 KB Output is correct
13 Correct 71 ms 8488 KB Output is correct
14 Correct 77 ms 8556 KB Output is correct
15 Correct 79 ms 8608 KB Output is correct
16 Correct 73 ms 8556 KB Output is correct
17 Correct 71 ms 8556 KB Output is correct
18 Correct 75 ms 8556 KB Output is correct
19 Correct 71 ms 8528 KB Output is correct
20 Correct 72 ms 8540 KB Output is correct
21 Correct 78 ms 8556 KB Output is correct
22 Correct 78 ms 8536 KB Output is correct
23 Correct 73 ms 8376 KB Output is correct
24 Correct 75 ms 8556 KB Output is correct
25 Correct 73 ms 8556 KB Output is correct
26 Correct 291 ms 14588 KB Output is correct
27 Correct 286 ms 14432 KB Output is correct
28 Correct 287 ms 14944 KB Output is correct
29 Correct 283 ms 14688 KB Output is correct
30 Correct 287 ms 14540 KB Output is correct
31 Correct 75 ms 8556 KB Output is correct
32 Correct 290 ms 14816 KB Output is correct
33 Correct 74 ms 8552 KB Output is correct
34 Correct 280 ms 14556 KB Output is correct
35 Correct 289 ms 14816 KB Output is correct
36 Correct 290 ms 14432 KB Output is correct
37 Correct 292 ms 14644 KB Output is correct
38 Correct 77 ms 8540 KB Output is correct
39 Correct 320 ms 14688 KB Output is correct
40 Correct 334 ms 14560 KB Output is correct
41 Correct 286 ms 14432 KB Output is correct
42 Correct 285 ms 14816 KB Output is correct
43 Correct 285 ms 15080 KB Output is correct
44 Correct 76 ms 8556 KB Output is correct
45 Correct 336 ms 14688 KB Output is correct
46 Correct 336 ms 14688 KB Output is correct
47 Correct 76 ms 8684 KB Output is correct
48 Correct 293 ms 14736 KB Output is correct
49 Correct 288 ms 14688 KB Output is correct
50 Correct 287 ms 14944 KB Output is correct
51 Correct 290 ms 14560 KB Output is correct
52 Correct 291 ms 14432 KB Output is correct
53 Correct 289 ms 14612 KB Output is correct
54 Correct 286 ms 14544 KB Output is correct
55 Correct 74 ms 8668 KB Output is correct
56 Correct 695 ms 35120 KB Output is correct
57 Correct 714 ms 35412 KB Output is correct
58 Correct 286 ms 14560 KB Output is correct
59 Correct 74 ms 8428 KB Output is correct
60 Correct 75 ms 8556 KB Output is correct
61 Correct 732 ms 35276 KB Output is correct
62 Correct 285 ms 14676 KB Output is correct
63 Correct 788 ms 40500 KB Output is correct
64 Correct 779 ms 35124 KB Output is correct
65 Correct 287 ms 14544 KB Output is correct
66 Correct 792 ms 36560 KB Output is correct
67 Correct 334 ms 14560 KB Output is correct
68 Correct 287 ms 14272 KB Output is correct
69 Correct 682 ms 35392 KB Output is correct
70 Correct 290 ms 14928 KB Output is correct
71 Correct 724 ms 35144 KB Output is correct
72 Correct 999 ms 37672 KB Output is correct
73 Correct 75 ms 8556 KB Output is correct
74 Correct 736 ms 40532 KB Output is correct
75 Correct 772 ms 38688 KB Output is correct
76 Correct 287 ms 14432 KB Output is correct
77 Correct 284 ms 14560 KB Output is correct
78 Correct 699 ms 34852 KB Output is correct
79 Correct 741 ms 41380 KB Output is correct
80 Correct 288 ms 14672 KB Output is correct
81 Correct 309 ms 14632 KB Output is correct
82 Correct 73 ms 8556 KB Output is correct
83 Correct 76 ms 8684 KB Output is correct
84 Correct 287 ms 14684 KB Output is correct
85 Correct 760 ms 37136 KB Output is correct
86 Correct 301 ms 14632 KB Output is correct
87 Correct 734 ms 34920 KB Output is correct
88 Correct 76 ms 8556 KB Output is correct
89 Correct 726 ms 35300 KB Output is correct
90 Correct 754 ms 37376 KB Output is correct
91 Correct 810 ms 41604 KB Output is correct
92 Correct 672 ms 35772 KB Output is correct
93 Correct 293 ms 14560 KB Output is correct
94 Correct 81 ms 8684 KB Output is correct
95 Correct 751 ms 47072 KB Output is correct
96 Correct 1204 ms 50576 KB Output is correct
97 Correct 337 ms 14688 KB Output is correct
98 Correct 77 ms 8680 KB Output is correct
99 Correct 758 ms 39976 KB Output is correct
100 Correct 285 ms 14560 KB Output is correct
101 Correct 731 ms 35924 KB Output is correct
102 Correct 751 ms 44036 KB Output is correct
103 Correct 294 ms 14852 KB Output is correct
104 Correct 286 ms 14816 KB Output is correct
105 Correct 283 ms 14448 KB Output is correct
106 Correct 297 ms 14492 KB Output is correct
107 Correct 288 ms 14560 KB Output is correct
108 Correct 2013 ms 131860 KB Output is correct
109 Correct 2165 ms 136020 KB Output is correct
110 Execution timed out 3085 ms 132924 KB Time limit exceeded
111 Halted 0 ms 0 KB -