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Submission #386556

# Submission time Handle Problem Language Result Execution time Memory
386556 2021-04-06T19:32:51 Z PurpleCrayon Meetings 2 (JOI21_meetings2) C++17
100 / 100
 695 ms 44996 KB 
#include <bits/stdc++.h>
using namespace std;

#define ar array
#define sz(v) int(v.size())
const int MAXN = 2e5+10, MAXL = 18, INF = 1e9+10;

int n, depth[MAXN], anc[MAXN][MAXL], st[MAXN], en[MAXN], tt=0;
vector<int> adj[MAXN];

//start lca
void init_lca(int c=0, int p=-1, int d=0){
	depth[c]=d, anc[c][0]=p;
    st[c] = tt++;
	for (int i=1; i < MAXL; i++) anc[c][i] = (anc[c][i-1]==-1?-1:anc[anc[c][i-1]][i-1]);
	for (auto nxt : adj[c]) if (nxt != p) init_lca(nxt, c, d+1);
    en[c] = tt-1;
}
int jmp(int a, int h){
	for (int i = 0; i < MAXL; i++) if ((h>>i)&1) a = anc[a][i];
	return a;
}
int lca(int a, int b){
	if (depth[a] < depth[b]) swap(a, b);
	a = jmp(a, depth[a]-depth[b]);
	if (a==b) return a;
	for (int i = MAXL-1; i >= 0; i--){
		if (anc[a][i] != anc[b][i]) a = anc[a][i], b = anc[b][i];
	}
	assert(anc[a][0]==anc[b][0]);
	return anc[a][0];
}
int dist(int a, int b){ return depth[a]+depth[b]-2*depth[lca(a, b)]; }
//end lca

int sub[MAXN], ans[MAXN];

int dfs1(int c=0, int p=-1){
    sub[c] = 1;
    for (auto nxt : adj[c]) if (nxt != p) sub[c] += dfs1(nxt, c);
    return sub[c];
}

struct pt_upd {
    int n, t[4*MAXN];
    void init(int _n){ n=_n; memset(t, -1, sizeof(t)); }
    void upd(int v, int tl, int tr, int pos, int nv){
        if (pos < tl || pos > tr) return;
        if (tl == tr) {
            t[v] = nv;
            return;
        }
        int tm=(tl+tr)/2;
        upd(2*v, tl, tm, pos, nv), upd(2*v+1, tm+1, tr, pos, nv);
        t[v] = max(t[2*v], t[2*v+1]);
    }
    void upd(int pos, int nv){ upd(1, 0, n-1, pos, nv); }
    int qry(int v, int tl, int tr, int l, int r) {
        if (r < tl || l > tr) return -1;
        if (l <= tl && tr <= r) return t[v];
        int tm=(tl+tr)/2;
        return max(qry(2*v, tl, tm, l, r), qry(2*v+1, tm+1, tr, l, r));
    }
    int qry(int l, int r){ return qry(1, 0, n-1, l, r); }
} seg1;
struct rng_upd {
    int n, t[4*MAXN];
    void init(int _n){ n=_n; fill(t, t+4*n, INF); }
    void upd(int v, int tl, int tr, int l, int r, int val){
        if (r < tl || l > tr) return;
        if (l <= tl && tr <= r) {
            t[v] = min(t[v], val);
            return;
        }
        int tm=(tl+tr)/2;
        upd(2*v, tl, tm, l, r, val), upd(2*v+1, tm+1, tr, l, r, val);
    }
    void upd(int l, int r, int nv){ upd(1, 0, n-1, l, r, nv); }
    int qry(int v, int tl, int tr, int pos) {
        if (tl == tr) return t[v];
        int ans=t[v], tm = (tl+tr)/2;
        if (pos <= tm)
            ans = min(ans, qry(2*v, tl, tm, pos));
        else
            ans = min(ans, qry(2*v+1, tm+1, tr, pos));
        return ans;
    }
    int qry(int pos){ return qry(1, 0, n-1, pos); }
} seg2;

int main(){
    ios::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 0; i < n-1; i++){
        int a, b; cin >> a >> b, --a, --b;
        adj[a].push_back(b), adj[b].push_back(a);
    }
    init_lca();
    dfs1();

    vector<int> p1(n); iota(p1.begin(), p1.end(), 0);
    sort(p1.begin(), p1.end(), [&](int i, int j){ return sub[i] < sub[j]; });

    vector<bool> is_lf(n);
    ar<int, 2> diam{-1, -1};

    vector<int> p2(n-1); iota(p2.begin(), p2.end(), 1);
    sort(p2.begin(), p2.end(), [&](int i, int j){ return n-sub[i] < n-sub[j]; });
    seg1.init(n); seg2.init(n);
    int up_len = -1;

    vector<int> lf;

    int ptr1=n-1, ptr2=n-2;
    for (int i = n; i >= 1; i--) {
        if (i&1){ ans[i] = 1; continue; }
        int v=i/2;
        while (ptr1>=0&&sub[p1[ptr1]]>=v) {
            int j = p1[ptr1];
            
            //cerr << "add down " << j << " for answer " << i << endl;

            if (sz(lf)<=2) {
                if (j){
                    if (is_lf[anc[j][0]]) {
                        lf.erase(find(lf.begin(), lf.end(), anc[j][0]));
                        is_lf[anc[j][0]] = 0;
                    }
                    is_lf[j] = 1;
                    lf.push_back(j);
                }
            }
            if (sz(lf) == 2) {
                diam = {lf[0], lf[1]};
            } else if (sz(lf) > 2) {
                int d1=dist(diam[0], diam[1]), d2=dist(diam[0], j), d3=dist(diam[1], j);
                if (d1 == max({d1, d2, d3})) {
                } else if (d2 == max({d1, d2, d3})) {
                    diam = {diam[0], j};
                } else if (d3 == max({d1, d2, d3})) {
                    diam = {diam[1], j};
                } else assert(false);
            }
            seg1.upd(st[j], depth[j]);
            up_len = max(up_len, depth[j]-seg2.qry(st[j])); 

            ptr1--;
        }
        while (ptr2>=0&&n-sub[p2[ptr2]]>=v) {
            int j = p2[ptr2];
            //cerr << "add up " << j << " for answer " << i << endl;
            
            up_len = max(up_len, seg1.qry(st[j], en[j])-(depth[j]-1));
            seg2.upd(st[j], en[j], (depth[j]-1));

            ptr2--;
        }
        //cerr << "diam: " << i << ' ' << diam[0] << ' ' << diam[1] << ' ' << sz(lf) << endl;

        ans[i] = 1+up_len;
        if (sz(lf) >= 2) ans[i] = max(ans[i], 1+dist(diam[0], diam[1]));
        ans[i] = max(ans[i], 1);
    }
    for (int i = 1; i <= n; i++) cout << ans[i] << '\n';
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8172 KB Output is correct
2 Correct 6 ms 8172 KB Output is correct
3 Correct 6 ms 8172 KB Output is correct
4 Correct 6 ms 8172 KB Output is correct
5 Correct 6 ms 8172 KB Output is correct
6 Correct 6 ms 8172 KB Output is correct
7 Correct 6 ms 8172 KB Output is correct
8 Correct 6 ms 8172 KB Output is correct
9 Correct 6 ms 8172 KB Output is correct
10 Correct 6 ms 8172 KB Output is correct
11 Correct 6 ms 8172 KB Output is correct
12 Correct 5 ms 8172 KB Output is correct
13 Correct 6 ms 8172 KB Output is correct
14 Correct 7 ms 8172 KB Output is correct
15 Correct 6 ms 8172 KB Output is correct
16 Correct 6 ms 8172 KB Output is correct
17 Correct 6 ms 8172 KB Output is correct
18 Correct 6 ms 8172 KB Output is correct
19 Correct 6 ms 8172 KB Output is correct
20 Correct 6 ms 8172 KB Output is correct
21 Correct 6 ms 8172 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8172 KB Output is correct
2 Correct 6 ms 8172 KB Output is correct
3 Correct 6 ms 8172 KB Output is correct
4 Correct 6 ms 8172 KB Output is correct
5 Correct 6 ms 8172 KB Output is correct
6 Correct 6 ms 8172 KB Output is correct
7 Correct 6 ms 8172 KB Output is correct
8 Correct 6 ms 8172 KB Output is correct
9 Correct 6 ms 8172 KB Output is correct
10 Correct 6 ms 8172 KB Output is correct
11 Correct 6 ms 8172 KB Output is correct
12 Correct 5 ms 8172 KB Output is correct
13 Correct 6 ms 8172 KB Output is correct
14 Correct 7 ms 8172 KB Output is correct
15 Correct 6 ms 8172 KB Output is correct
16 Correct 6 ms 8172 KB Output is correct
17 Correct 6 ms 8172 KB Output is correct
18 Correct 6 ms 8172 KB Output is correct
19 Correct 6 ms 8172 KB Output is correct
20 Correct 6 ms 8172 KB Output is correct
21 Correct 6 ms 8172 KB Output is correct
22 Correct 11 ms 8812 KB Output is correct
23 Correct 11 ms 8812 KB Output is correct
24 Correct 11 ms 8812 KB Output is correct
25 Correct 12 ms 8832 KB Output is correct
26 Correct 12 ms 8812 KB Output is correct
27 Correct 12 ms 8812 KB Output is correct
28 Correct 12 ms 8812 KB Output is correct
29 Correct 12 ms 8812 KB Output is correct
30 Correct 11 ms 8812 KB Output is correct
31 Correct 12 ms 8812 KB Output is correct
32 Correct 12 ms 8940 KB Output is correct
33 Correct 11 ms 8940 KB Output is correct
34 Correct 11 ms 8812 KB Output is correct
35 Correct 11 ms 8832 KB Output is correct
36 Correct 12 ms 8832 KB Output is correct
37 Correct 11 ms 8812 KB Output is correct
38 Correct 14 ms 8812 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8172 KB Output is correct
2 Correct 6 ms 8172 KB Output is correct
3 Correct 6 ms 8172 KB Output is correct
4 Correct 6 ms 8172 KB Output is correct
5 Correct 6 ms 8172 KB Output is correct
6 Correct 6 ms 8172 KB Output is correct
7 Correct 6 ms 8172 KB Output is correct
8 Correct 6 ms 8172 KB Output is correct
9 Correct 6 ms 8172 KB Output is correct
10 Correct 6 ms 8172 KB Output is correct
11 Correct 6 ms 8172 KB Output is correct
12 Correct 5 ms 8172 KB Output is correct
13 Correct 6 ms 8172 KB Output is correct
14 Correct 7 ms 8172 KB Output is correct
15 Correct 6 ms 8172 KB Output is correct
16 Correct 6 ms 8172 KB Output is correct
17 Correct 6 ms 8172 KB Output is correct
18 Correct 6 ms 8172 KB Output is correct
19 Correct 6 ms 8172 KB Output is correct
20 Correct 6 ms 8172 KB Output is correct
21 Correct 6 ms 8172 KB Output is correct
22 Correct 11 ms 8812 KB Output is correct
23 Correct 11 ms 8812 KB Output is correct
24 Correct 11 ms 8812 KB Output is correct
25 Correct 12 ms 8832 KB Output is correct
26 Correct 12 ms 8812 KB Output is correct
27 Correct 12 ms 8812 KB Output is correct
28 Correct 12 ms 8812 KB Output is correct
29 Correct 12 ms 8812 KB Output is correct
30 Correct 11 ms 8812 KB Output is correct
31 Correct 12 ms 8812 KB Output is correct
32 Correct 12 ms 8940 KB Output is correct
33 Correct 11 ms 8940 KB Output is correct
34 Correct 11 ms 8812 KB Output is correct
35 Correct 11 ms 8832 KB Output is correct
36 Correct 12 ms 8832 KB Output is correct
37 Correct 11 ms 8812 KB Output is correct
38 Correct 14 ms 8812 KB Output is correct
39 Correct 552 ms 37368 KB Output is correct
40 Correct 538 ms 36880 KB Output is correct
41 Correct 545 ms 37484 KB Output is correct
42 Correct 576 ms 37996 KB Output is correct
43 Correct 565 ms 37868 KB Output is correct
44 Correct 576 ms 37868 KB Output is correct
45 Correct 695 ms 41964 KB Output is correct
46 Correct 561 ms 44996 KB Output is correct
47 Correct 458 ms 38116 KB Output is correct
48 Correct 381 ms 38368 KB Output is correct
49 Correct 577 ms 38420 KB Output is correct
50 Correct 385 ms 38372 KB Output is correct
51 Correct 462 ms 44388 KB Output is correct