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Submission #595540

# Submission time Handle Problem Language Result Execution time Memory
595540 2022-07-13T20:02:56 Z rainliofficial Dynamic Diameter (CEOI19_diameter) C++17
100 / 100
 357 ms 86476 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define sz(x) (int)x.size()
#define f first
#define s second

/* 
Date: 2022/07/12 19:14
Problem Link: https://dmoj.ca/problem/ceoi19p2/
Topic(s): Segment tree, Euler tour
Time Spent:
Solution Notes:
By creating a segment tree, each node holds 4 values:
1. d_i = distance to the root
2. max(d_l - 2*d_m)
3. max(d_r - 2*d_m)
4. max(d_l + d_r - 2*d_m)
*/


const int MAXN = 1e5+5;
const ll INF = 5e17;
int n, q, in[MAXN], out[MAXN], dep[MAXN], timer = 0;
ll dp[MAXN];
vector<pair<int, ll>> arr[MAXN];
vector<int> tour;
ll w;

void dfs(int at, int p, int d, ll dist){
    tour.push_back(at);
    in[at] = timer++;
    dep[at] = d;
    dp[at] = dist;
    for (auto edge : arr[at]){
        if (edge.f != p){
            dfs(edge.f, at, d+1, dist + edge.s);
            tour.push_back(at);
            timer++;
        }
    }
    tour.push_back(at);
    out[at] = timer++;
}

struct Node{
    ll di_max, di_min, pre, suf, ans;
};

struct segtree{
    int n;
    Node identity = {0, INF, -INF, -INF, 0};
    vector<Node> seg;
    vector<ll> lazy;
    vector<ll> arr;
    segtree(int n){
        this->n = n;
        seg.resize(4*n, identity);
        lazy.resize(4*n);
    }
    void build(vector<ll>& arr){
        this->arr = arr;
        build(0, 0, n-1);
    }
    void build(int node, int l, int r){
        if (l == r) {
			seg[node] = {arr[l], arr[l], -arr[l], -arr[l], 0};
			return;
		}
		int mid = (l + r) / 2;
		build(node * 2 + 1, l, mid);
		build(node * 2 + 2, mid + 1, r);
		// change this
		seg[node] = combine(seg[node * 2 + 1], seg[node * 2 + 2]);
    }
    ll query(){
        return seg[0].ans;
    }
    void update(int a, int b, ll x) { // inclusive 0-indexed
		update(0, 0, n-1, a, b, x);
	}
    void update(int node, int l, int r, int a, int b, ll x) {
		int numElements = r - l + 1;
		if (a <= l && r <= b) { 
			apply(node, l, r, x);
			return;
		}
		prop(node, l, r);
		int mid = (l + r) / 2;
		if (a <= mid) {
			update(node * 2 + 1, l, mid, a, b, x);
		}
		if (b > mid) {
			update(node * 2 + 2, mid + 1, r, a, b, x);
		}
		// change this
		seg[node] = combine(seg[node * 2 + 1], seg[node * 2 + 2]);

	}
    void prop(int node, int l, int r) { // propagate the "lazy value"
		if (lazy[node] != 0) {
			int mid = (l + r) / 2;
			// change this
			apply(node*2+1, l, mid, lazy[node]);
			apply(node*2+2, mid+1, r, lazy[node]);
			lazy[node] = 0;
		}
	}
	void apply(ll node, ll l, ll r, ll x){
        seg[node].di_min += x;
        seg[node].di_max += x;
        seg[node].pre -= x;
        seg[node].suf -= x;
        lazy[node] += x;
    }
	Node combine(Node a, Node b){
        ll di_min = min(a.di_min, b.di_min);
        ll di_max = max(a.di_max, b.di_max);
        ll pre = max({a.pre, b.pre, a.di_max - 2*b.di_min});
        ll suf = max({a.suf, b.suf, b.di_max - 2*a.di_min});
        ll ans = max({a.ans, b.ans, a.pre + b.di_max, b.suf + a.di_max});
        return {di_max, di_min, pre, suf, ans};
    }
};


int main(){
    cin.tie(0); ios_base::sync_with_stdio(0);
    // freopen("file.in", "r", stdin);
    // freopen("file.out", "w", stdout);
    cin >> n >> q >> w;
    vector<array<ll, 3>> edges(n-1);
    for (int i=0; i<n-1; i++){
        int a, b;
        ll c;
        cin >> a >> b >> c;
        a--; b--;
        edges[i] = {a, b, c};
        arr[a].push_back({b, c});
        arr[b].push_back({a, c});
    }
    dfs(0, -1, 0, 0);
    vector<ll> segtreeInit;
    for (int i=0; i<sz(tour); i++){
        segtreeInit.push_back(dp[tour[i]]);
    }
    segtree st(sz(tour));
    st.build(segtreeInit);
    ll last = 0;
    for (int i=0; i<q; i++){
        int a;
        ll b;
        cin >> a >> b;
        a = (a + last)%(n-1);
        b = (b + last)%w;
        int subtree = dep[edges[a][0]] > dep[edges[a][1]] ? edges[a][0] : edges[a][1];
        st.update(in[subtree], out[subtree], b - edges[a][2]);
        edges[a][2] = b;
        last = st.query();
        cout << last << "\n";
    }
}

Compilation message

diameter.cpp: In member function 'void segtree::update(int, int, int, int, int, ll)':
diameter.cpp:85:7: warning: unused variable 'numElements' [-Wunused-variable]
   85 |   int numElements = r - l + 1;
      |       ^~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2680 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2680 KB Output is correct
7 Correct 1 ms 2644 KB Output is correct
8 Correct 2 ms 2676 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2676 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2680 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2684 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct

Subtask #2
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2680 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2680 KB Output is correct
7 Correct 1 ms 2644 KB Output is correct
8 Correct 2 ms 2676 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2676 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2680 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2684 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 6 ms 3540 KB Output is correct
20 Correct 5 ms 3456 KB Output is correct
21 Correct 7 ms 3436 KB Output is correct
22 Correct 6 ms 3540 KB Output is correct
23 Correct 9 ms 6548 KB Output is correct
24 Correct 8 ms 6484 KB Output is correct
25 Correct 9 ms 6524 KB Output is correct
26 Correct 9 ms 6868 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 8 ms 2900 KB Output is correct
5 Correct 32 ms 3848 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 3028 KB Output is correct
8 Correct 2 ms 3028 KB Output is correct
9 Correct 3 ms 3076 KB Output is correct
10 Correct 10 ms 3320 KB Output is correct
11 Correct 41 ms 4300 KB Output is correct
12 Correct 5 ms 6356 KB Output is correct
13 Correct 5 ms 6356 KB Output is correct
14 Correct 6 ms 6484 KB Output is correct
15 Correct 14 ms 6696 KB Output is correct
16 Correct 54 ms 7844 KB Output is correct
17 Correct 64 ms 75176 KB Output is correct
18 Correct 63 ms 75148 KB Output is correct
19 Correct 66 ms 75352 KB Output is correct
20 Correct 86 ms 75512 KB Output is correct
21 Correct 167 ms 76880 KB Output is correct

Subtask #4
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3412 KB Output is correct
2 Correct 9 ms 3592 KB Output is correct
3 Correct 29 ms 4040 KB Output is correct
4 Correct 55 ms 4732 KB Output is correct
5 Correct 11 ms 10108 KB Output is correct
6 Correct 16 ms 10320 KB Output is correct
7 Correct 42 ms 10832 KB Output is correct
8 Correct 75 ms 11652 KB Output is correct
9 Correct 37 ms 39612 KB Output is correct
10 Correct 45 ms 39664 KB Output is correct
11 Correct 87 ms 40380 KB Output is correct
12 Correct 129 ms 41144 KB Output is correct
13 Correct 71 ms 76416 KB Output is correct
14 Correct 81 ms 76452 KB Output is correct
15 Correct 122 ms 77196 KB Output is correct
16 Correct 173 ms 78212 KB Output is correct
17 Correct 191 ms 77796 KB Output is correct

Subtask #5
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 233 ms 80128 KB Output is correct
2 Correct 233 ms 80156 KB Output is correct
3 Correct 230 ms 80152 KB Output is correct
4 Correct 231 ms 80180 KB Output is correct
5 Correct 215 ms 80084 KB Output is correct
6 Correct 203 ms 79960 KB Output is correct
7 Correct 248 ms 82616 KB Output is correct
8 Correct 250 ms 82664 KB Output is correct
9 Correct 239 ms 82564 KB Output is correct
10 Correct 238 ms 82604 KB Output is correct
11 Correct 238 ms 82416 KB Output is correct
12 Correct 223 ms 81616 KB Output is correct
13 Correct 267 ms 86328 KB Output is correct
14 Correct 278 ms 86424 KB Output is correct
15 Correct 272 ms 86332 KB Output is correct
16 Correct 269 ms 86468 KB Output is correct
17 Correct 306 ms 85792 KB Output is correct
18 Correct 251 ms 82936 KB Output is correct
19 Correct 278 ms 86348 KB Output is correct
20 Correct 303 ms 86368 KB Output is correct
21 Correct 357 ms 86476 KB Output is correct
22 Correct 299 ms 86324 KB Output is correct
23 Correct 316 ms 85736 KB Output is correct
24 Correct 255 ms 82992 KB Output is correct

Subtask #6
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2680 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2680 KB Output is correct
7 Correct 1 ms 2644 KB Output is correct
8 Correct 2 ms 2676 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2676 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2680 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2684 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 6 ms 3540 KB Output is correct
20 Correct 5 ms 3456 KB Output is correct
21 Correct 7 ms 3436 KB Output is correct
22 Correct 6 ms 3540 KB Output is correct
23 Correct 9 ms 6548 KB Output is correct
24 Correct 8 ms 6484 KB Output is correct
25 Correct 9 ms 6524 KB Output is correct
26 Correct 9 ms 6868 KB Output is correct
27 Correct 2 ms 2644 KB Output is correct
28 Correct 2 ms 2644 KB Output is correct
29 Correct 2 ms 2644 KB Output is correct
30 Correct 8 ms 2900 KB Output is correct
31 Correct 32 ms 3848 KB Output is correct
32 Correct 2 ms 2644 KB Output is correct
33 Correct 2 ms 3028 KB Output is correct
34 Correct 2 ms 3028 KB Output is correct
35 Correct 3 ms 3076 KB Output is correct
36 Correct 10 ms 3320 KB Output is correct
37 Correct 41 ms 4300 KB Output is correct
38 Correct 5 ms 6356 KB Output is correct
39 Correct 5 ms 6356 KB Output is correct
40 Correct 6 ms 6484 KB Output is correct
41 Correct 14 ms 6696 KB Output is correct
42 Correct 54 ms 7844 KB Output is correct
43 Correct 64 ms 75176 KB Output is correct
44 Correct 63 ms 75148 KB Output is correct
45 Correct 66 ms 75352 KB Output is correct
46 Correct 86 ms 75512 KB Output is correct
47 Correct 167 ms 76880 KB Output is correct
48 Correct 3 ms 3412 KB Output is correct
49 Correct 9 ms 3592 KB Output is correct
50 Correct 29 ms 4040 KB Output is correct
51 Correct 55 ms 4732 KB Output is correct
52 Correct 11 ms 10108 KB Output is correct
53 Correct 16 ms 10320 KB Output is correct
54 Correct 42 ms 10832 KB Output is correct
55 Correct 75 ms 11652 KB Output is correct
56 Correct 37 ms 39612 KB Output is correct
57 Correct 45 ms 39664 KB Output is correct
58 Correct 87 ms 40380 KB Output is correct
59 Correct 129 ms 41144 KB Output is correct
60 Correct 71 ms 76416 KB Output is correct
61 Correct 81 ms 76452 KB Output is correct
62 Correct 122 ms 77196 KB Output is correct
63 Correct 173 ms 78212 KB Output is correct
64 Correct 191 ms 77796 KB Output is correct
65 Correct 233 ms 80128 KB Output is correct
66 Correct 233 ms 80156 KB Output is correct
67 Correct 230 ms 80152 KB Output is correct
68 Correct 231 ms 80180 KB Output is correct
69 Correct 215 ms 80084 KB Output is correct
70 Correct 203 ms 79960 KB Output is correct
71 Correct 248 ms 82616 KB Output is correct
72 Correct 250 ms 82664 KB Output is correct
73 Correct 239 ms 82564 KB Output is correct
74 Correct 238 ms 82604 KB Output is correct
75 Correct 238 ms 82416 KB Output is correct
76 Correct 223 ms 81616 KB Output is correct
77 Correct 267 ms 86328 KB Output is correct
78 Correct 278 ms 86424 KB Output is correct
79 Correct 272 ms 86332 KB Output is correct
80 Correct 269 ms 86468 KB Output is correct
81 Correct 306 ms 85792 KB Output is correct
82 Correct 251 ms 82936 KB Output is correct
83 Correct 278 ms 86348 KB Output is correct
84 Correct 303 ms 86368 KB Output is correct
85 Correct 357 ms 86476 KB Output is correct
86 Correct 299 ms 86324 KB Output is correct
87 Correct 316 ms 85736 KB Output is correct
88 Correct 255 ms 82992 KB Output is correct
89 Correct 224 ms 79188 KB Output is correct
90 Correct 236 ms 79532 KB Output is correct
91 Correct 243 ms 80896 KB Output is correct
92 Correct 243 ms 80820 KB Output is correct
93 Correct 256 ms 83192 KB Output is correct
94 Correct 266 ms 82364 KB Output is correct
95 Correct 269 ms 83800 KB Output is correct
96 Correct 291 ms 82904 KB Output is correct
97 Correct 265 ms 83720 KB Output is correct
98 Correct 293 ms 85688 KB Output is correct
99 Correct 267 ms 83468 KB Output is correct
100 Correct 266 ms 83516 KB Output is correct