Submission #711994

#	Time	Username	Problem	Language	Result	Execution time	Memory
711994		ssense	Dynamic Diameter (CEOI19_diameter)	C++17	100 / 100	391 ms	84488 KiB

diameter

#include <bits/stdc++.h>
#define startt ios_base::sync_with_stdio(false);cin.tie(0);
typedef long long  ll;
using namespace std;
#define vint vector<int>
#define all(v) v.begin(), v.end()
#define MOD 1000000007
#define MOD2 998244353
#define MX 1000000000
#define MXL 1000000000000000000
#define PI (ld)2*acos(0.0)
#define pb push_back
#define sc second
#define fr first
#define int long long
#define endl '\n'
#define ld long double
#define NO cout << "NO" << endl
#define YES cout << "YES" << endl
int ceildiv(int one, int two) {if (one % two == 0) {return one / two;}else {return one / two + 1;}} int power(int n, int pow, int m) {if (pow == 0) return 1;if (pow % 2 == 0) {ll x = power(n, pow / 2, m);return (x * x) % m;}else return (power(n, pow - 1, m) * n) % m;} int gcd(int a, int b) { if (!b)return a; return gcd(b, a % b);} int factorial(int n, int mod) {if (n > 1)return (n * factorial(n - 1, mod)) % mod; else return 1;} int lcm(int a, int b) {return (a * b) / gcd(a, b);} vector<int> read(int n) {vector<int> a; for (int i = 0; i < n; i++) { int x; cin >> x; a.pb(x);} return a;}struct prefix_sum{vint pref;void build(vint a){pref.pb(0);for(int i = 0; i < a.size(); i++){pref.pb(pref.back()+a[i]);}}int get(int l, int r){return pref[r]-pref[l-1];}};//mesanu

int n, q, w;
vector<vector<pair<int, int>>> adj;
vector<int> tin, tout;

vector<int> tour;

void dfs(int u, int p, int dist)
{
    tin[u] = tour.size();
    tour.push_back(dist);
    for(auto v : adj[u])
    {
        if(v.first != p)
        {
            dfs(v.first, u, dist+v.second);
            tour.push_back(dist);
        }
    }
    tout[u] = tour.size();
    tour.push_back(dist);
}

struct node
{
    int d_max, d_min, d_left, d_right, ans;
};

vector<node> seg;
vector<int> lazy;

node merge(node a, node b)
{
    node temp;
    temp.ans = max({a.d_right + b.d_max, b.d_left + a.d_max, a.ans, b.ans});
    temp.d_right = max({a.d_right, b.d_right, a.d_max-2*b.d_min});
    temp.d_left = max({a.d_left, b.d_left, b.d_max-2*a.d_min});
    temp.d_max = max(a.d_max, b.d_max);
    temp.d_min = min(a.d_min, b.d_min);
    return temp;
}

void build(int l, int r, int v)
{
    lazy[v] = 0;
    if(l == r)
    {
        node temp;
        temp.d_max = tour[l];
        temp.d_min = tour[l];
        temp.ans = 0;
        temp.d_right = -tour[l];
        temp.d_left = -tour[l];
        seg[v] = temp;
        return;
    }
    build(l, (l+r)/2, 2*v+1);
    build((l+r)/2+1, r, 2*v+2);
    seg[v] = merge(seg[2*v+1], seg[2*v+2]);
}

void push(int v, int l, int r)
{
    if(lazy[v] == 0)
    {
        return;
    }
    seg[v].d_max+=lazy[v];
    seg[v].d_min+=lazy[v];
    seg[v].d_left-=lazy[v];
    seg[v].d_right-=lazy[v];
    if(l != r){
        lazy[2*v+1]+=lazy[v];
        lazy[2*v+2]+=lazy[v];
    }
    lazy[v] = 0;
}

void modif(int v, int l, int r, int tl, int tr, int val){
    push(v, l, r);
    if(l > tr || r < tl)return;

    if(l >= tl && r <= tr){
        lazy[v]+=val;
        push(v, l , r);
        return;
    }

    int mid = (l + r) >> 1;

    modif(2 * v + 1, l, mid, tl, tr, val);
    modif(2 * v + 2, mid + 1, r, tl, tr, val);

    seg[v] = merge(seg[2*v+1], seg[2*v+2]);
}




int32_t main(){
    startt
    cin >> n >> q >> w;
    adj.resize(n+1);
    tin.resize(n+1);
    tout.resize(n+1);
    map<pair<int, int>, int> mp;
    vector<pair<pair<int, int>, int>> ww;
    for(int i = 0; i < n-1; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].pb({v, w});
        adj[v].pb({u, w});
        ww.push_back({{u, v}, w});
    }
    dfs(1, 0, 0);
    seg.resize(4*tour.size()+4);
    lazy.resize(4*tour.size()+4);
    build(0, tour.size(), 0);
    //cout << seg[0].ans << endl;
    int last = 0;
    for(int i = 0; i < q; i++)
    {
        int dd, ee;
        cin >> dd >> ee;
        int d = (dd+last)%(n-1), e = (ee+last)%w;
        if(tin[ww[d].fr.fr] > tin[ww[d].fr.sc])
        {
            swap(ww[d].fr.fr, ww[d].fr.sc);
        }
        modif(0, 0, tour.size(), tin[ww[d].fr.sc], tout[ww[d].fr.sc], e-ww[d].sc);
        if(n == 2)
        {
            cout << e << endl;
            last = e;
            continue;
        }
        ww[d].sc = e;
        last = max(seg[0].ans, seg[0].d_max);
        cout << last << endl;
    }
}

Compilation message (stderr)

diameter.cpp: In member function 'void prefix_sum::build(std::vector<long long int>)':
diameter.cpp:20:667: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 | int ceildiv(int one, int two) {if (one % two == 0) {return one / two;}else {return one / two + 1;}} int power(int n, int pow, int m) {if (pow == 0) return 1;if (pow % 2 == 0) {ll x = power(n, pow / 2, m);return (x * x) % m;}else return (power(n, pow - 1, m) * n) % m;} int gcd(int a, int b) { if (!b)return a; return gcd(b, a % b);} int factorial(int n, int mod) {if (n > 1)return (n * factorial(n - 1, mod)) % mod; else return 1;} int lcm(int a, int b) {return (a * b) / gcd(a, b);} vector<int> read(int n) {vector<int> a; for (int i = 0; i < n; i++) { int x; cin >> x; a.pb(x);} return a;}struct prefix_sum{vint pref;void build(vint a){pref.pb(0);for(int i = 0; i < a.size(); i++){pref.pb(pref.back()+a[i]);}}int get(int l, int r){return pref[r]-pref[l-1];}};//mesanu
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• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 7 / 7
• Subtask 4: 18 / 18
• Subtask 5: 24 / 24
• Subtask 6: 27 / 27