Submission #1067448

#	Time	Username	Problem	Language	Result	Execution time	Memory
1067448		TVSown	Dynamic Diameter (CEOI19_diameter)	C++17	24 / 100	5046 ms	53068 KiB

diameter

///*** Sown_Vipro ***///
/// ->TUYEN QUOC GIA<- ///

#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
#define F first
#define S second
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pair<int, int> >
#define all(a) a.begin(), a.end()
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = a; i >= b; --i)
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
#define szz(s) int(s.size())
const int N = 1e5 + 5, MAX = 1e6, MOD = 1e9 + 7;
const long long oo = 1e18 + 5;
int n, q, m, TIME;
long long W, lz[4 * N], res, d[N];
int in[N], out[N], ver[N], h[N];
vector<pi> e[N];

struct ed{
    int u, v;
    long long w;
} edge[N];

void euler(int u, int p){
    in[u] = ++m;
    out[u] = m;
    ver[m] = u;

    for(auto [v, w] : e[u]){
        if(v == p) continue;
        h[v] = h[u] + 1;
        d[v] = d[u] + w;
        euler(v, u);
    }

    if(p != 0){
        out[p] = ++m;
        ver[m] = p;
    }
}

struct node{
    long long du = oo, dv = -oo, duw = -oo, dwv = -oo, duwv = 0;
} st[4 * N];



void down(int id){
    st[2 * id].du += lz[id];
    st[2 * id].dv += lz[id];
    st[2 * id].duw -= lz[id];
    st[2 * id].dwv -= lz[id];
    lz[2 * id] += lz[id];

    st[2 * id + 1].du += lz[id];
    st[2 * id + 1].dv += lz[id];
    st[2 * id + 1].duw -= lz[id];
    st[2 * id + 1].dwv -= lz[id];
    lz[2 * id + 1] += lz[id];

    lz[id] = 0;
}

node Merge(node A, node B, int l, int r){
    node res;
    res.du = min(A.du, B.du);
    res.dv = max(A.dv, B.dv);

    res.duw = max({A.duw, B.duw, A.dv - 2 * B.du});
    res.dwv = max({A.dwv, B.dwv, B.dv - 2 * A.du});

    res.duwv = max({A.duwv, B.duwv, A.duw + B.dv, A.dv + B.dwv});
//    cout << l << " " << r << " " << A.duw << " " << B.dv << " " << A.dv << " " << B.dwv << "\n";
    return res;
}

void build(int id, int l, int r){
    if(l == r){
        st[id].du = st[id].dv = d[ver[l]];
        st[id].duw = st[id].dwv = -d[ver[l]];
        return;
    }
    int m = (l + r) / 2;
    build(2 * id, l, m);
    build(2 * id + 1, m + 1, r);
    st[id] = Merge(st[2 * id], st[2 * id + 1], l, r);
//    cout << l << " " << r << " " << id << " " << st[id].dv << "\n";
}

void update(int id, int l, int r, int u, int v, int x){
    if(l > v || r < u) return;

    if(u <= l && r <= v){
        st[id].du += x;
        st[id].dv += x;
        st[id].duw -= x;
        st[id].dwv -= x;
        lz[id] += x;
        return;
    }

    down(id);
    int m = (l + r) / 2;
    update(2 * id, l, m, u, v, x);
    update(2 * id + 1, m + 1, r, u, v, x);
    st[id] = Merge(st[2 * id], st[2 * id + 1], l, r);
//    cout << l << " " << r << " " << id << " " << st[id].dv << "\n";
}

void solve(){
    cin >> n >> q >> W;
    FOR(i, 1, n - 1){
        int u, v, w; cin >> u >> v >> w;
        e[u].pb({v, w});
        e[v].pb({u, w});
        edge[i] = {u, v, w};
    }
    euler(1, 0);

    build(1, 1, m);
//    FOR(i, 1, m) cout << ver[i] << " ";
//    cout << "\n";
//    cout << st[1].dv;
    while(q--){
        int d; long long e;
        cin >> d >> e;

        d = (d + res) % (n - 1) + 1;
        e = (e + res) % W;

//        cout << d << " " << e << " ";

        int u = edge[d].u, v = edge[d].v, w = edge[d].w;
        if(h[u] > h[v]) swap(u, v);
//        cout << u << " " << v << "\n";
        update(1, 1, m, in[v], out[v], e - w);
        res = st[1].duwv;
        cout << res << "\n";
        edge[d].w = e;
//        break;
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
//    inp("in.txt");
//    out("out.txt");
    int t = 1;
//    cin >> t;
    while(t--){
        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