Submission #373076

#	Time	Username	Problem	Language	Result	Execution time	Memory
373076		ACmachine	Dynamic Diameter (CEOI19_diameter)	C++17	24 / 100	5063 ms	13476 KiB

diameter

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)

const double EPS = 1e-9;
const int MOD = 1e9+7;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

void DBG(){cout << "]" << endl;}
template<typename T, typename ...U> void DBG(const T& head, const U... args){ cout << head << "; "; DBG(args...); }
#define dbg(...) cout << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__);
#define chk() cout << "Check at line(" << __LINE__ << ") hit." << endl;

template<class T, unsigned int U>
ostream& operator<<(ostream& out, const array<T, U> &v){out << "[";  REP(i, U) out << v[i] << ", ";  out << "]"; return out;}
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}

template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }

int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
    int n, q; ll w;
    cin >> n >> q; cin >> w;
    vector<vector<array<ll, 2>>> g(n);
    vector<array<ll, 3>> edges(n - 1);
    // centroids for full, but too hard to impl, impl at the end if time
    REP(i, n - 1){
        ll a, b, c;
        cin >> a >> b >> c;
        a--; b--;
        g[a].pb({b, i});
        g[b].pb({a, i});
        edges[i] = {a, b, c};
    }
    auto solve12 = [&](){
        int diam1, diam2;
        vector<ll> dist(n, 0);
        function<void(int, int)> dfs = [&](int v, int p){
            for(auto x : g[v]){
                if(x[0] == p) continue;
                ll weight = edges[x[1]][2];
                dist[x[0]] = dist[v] + weight;
                dfs(x[0], v);
            }
        };
        dfs(0, -1); diam1 = max_element(all(dist)) - dist.begin();
        dist[diam1] = 0; dfs(diam1, -1); diam2 = max_element(all(dist)) - dist.begin();
        ll last = 0;
        REP(i, q){
            ll d, e;
            cin >> d >> e;
            d = (d + last) % (n - 1);
            e = (e + last) % w;
            edges[d][2] = e;
            dist[diam1] = 0;
            dfs(diam1, -1); int nxt_diam2 = max_element(all(dist)) - dist.begin();
            ll nxt_diamw2 = *max_element(all(dist));
            dist[diam2] = 0; dfs(diam2, -1); int nxt_diam1 = max_element(all(dist)) - dist.begin();
            ll nxt_diamw1 = *max_element(all(dist));
            if(nxt_diamw1 > nxt_diamw2){
                last = nxt_diamw1;
                diam1 = nxt_diam1;
            }
            else{
                last = nxt_diamw2;
                diam2 = nxt_diam2;
            }
            cout << last << "\n";
        }
    };
    solve12();

    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27