Submission #971663

#	Time	Username	Problem	Language	Result	Execution time	Memory
971663		efedmrlr	Dynamic Diameter (CEOI19_diameter)	C++17	24 / 100	5037 ms	17772 KiB

diameter

// #pragma GCC optimize("O3,Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>

using namespace std;


#define lli long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()


void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}


const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e5+5;
const int ALPH = 26;
const int LGN = 25;
constexpr int MOD = 1e9+7;
int n,q,w;
vector<vector<array<int, 2> > > adj(N, vector<array<int, 2> >());
vector<array<int, 3> > edg(N);
vector<int> dist(N);
void dfs(int node, int par) {
    for(auto c : adj[node]) {
        if(c[0] == par) continue;
        dist[c[0]] = dist[node] + edg[c[1]][2];
        dfs(c[0], node);
    }
}

int get_diam() {
    dist[1] = 0;
    dfs(1, 0);
    int ind = 1;
    for(int i = 1; i <= n; i++) {
        if(dist[i] > dist[ind]) ind = i;
    }
    dist[ind] = 0;
    dfs(ind, 0);
    return *max_element(dist.begin(), dist.begin() + n + 1);
}

inline void solve() {
    cin >> n >> q >> w;
    edg.resize(n - 1);
    REP(i, n - 1) {
        cin >> edg[i][0] >> edg[i][1] >> edg[i][2];
        adj[edg[i][0]].pb({edg[i][1], i});
        adj[edg[i][1]].pb({edg[i][0], i});
    }
    int last = 0;
    REP(z, q) {
        int d, e;
        cin >> d >> e;
        d = (d + last) % (n - 1);
        e = (e + last) % w;
        edg[d][2] = e;
        last = get_diam();
        cout << last << "\n";
    }
}
 
signed main() {

    fastio();
    int test = 1;
    //cin>>test;
    while(test--) {
        solve();
    }
    
}

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