| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 895861 | math_rabbit_1028 | Dynamic Diameter (CEOI19_diameter) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef struct {
int idx;
ll val;
} pil;
const ll MOD = 998244353;
int n, q;
ll w;
ll edges[101010][3];
vector<pil> adj[101010];
int ch[101010], sz[101010];
vector<int> child[101010];
int par[101010];
void get_sz(int v, int par = -1) {
sz[v] = 1;
for (int i = 0; i < adj[v].size(); i++) {
int u = adj[v][i].idx;
if (ch[u] == 1) continue;
if (u == par) continue;
get_sz(u, v);
sz[v] += sz[u];
}
}
int get_cent(int tot, int v, int par = -1) {
for (int i = 0; i < adj[v].size(); i++) {
int u = adj[v][i].idx;
if (ch[u] == 1) continue;
if (u == par) continue;
if (sz[u] * 2 > tot) return get_cent(tot, u, v);
}
return v;
}
void cent(int v, int tot) {
get_sz(v);
v = get_cent(tot, v);
get_sz(v);
ch[v] = 1;
for (int i = 0; i < adj[v].size(); i++) {
int u = adj[v][i].idx;
if (ch[u] == 1) continue;
par[u] = v;
child[v].push_back(u);
cent(u, sz[u]);
}
}
int ord[202020], r = 0, in[101010], out[101010], depth[101010];
ll dis[101010];
void ett(int v, int par = -1) {
ord[++r] = v; in[v] = r;
for (int i = 0; i < adj[v].size(); i++) {
int u = adj[v][i].idx;
if (u == par) continue;
dis[u] = dis[v] + adj[v][i].val;
depth[u] = depth[v] + 1;
ett(u, v);
}
out[v] = r;
}
struct maxseg {
pil tree[808080];
ll lazy[808080];
pil mer(pil lt, pil rt) {
if (lt.val > rt.val) return lt;
if (lt.val < rt.val) return rt;
if (lt.val == rt.val) {
if (lt.idx > rt.idx) return lt;
else return rt;
}
}
void prop(int v) {
tree[v].val += lazy[v];
lazy[2*v] += lazy[v];
lazy[2*v+1] += lazy[v];
lazy[v] = 0;
}
void init(int v, int st, int ed) {
if (st == ed) {
tree[v] = {ord[st], dis[ord[st]]};
lazy[v] = 0;
return;
}
int mid = (st + ed) / 2;
init(2*v, st, mid);
init(2*v+1, mid+1, ed);
tree[v] = mer(tree[2*v], tree[2*v+1]);
}
void upd(int v, int st, int ed, int lt, int rt, ll diff) {
prop(v);
if (lt <= st && ed <= rt) {
lazy[v] = diff;
prop(v);
return;
}
if (st > rt || lt > ed) return;
int mid = (st + ed) / 2;
upd(2*v, st, mid, lt, rt, diff);
upd(2*v+1, mid+1, ed, lt, rt, diff);
tree[v] = mer(tree[2*v], tree[2*v+1]);
}
pil get(int v, int st, int ed, int lt, int rt) {
prop(v);
if (lt <= st && ed <= rt) return tree[v];
if (st > rt || lt > ed) return {-1, -1};
int mid = (st + ed) / 2;
return mer(get(2*v, st, mid, lt, rt), get(2*v+1, mid+1, ed, lt, rt));
}
} seg;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> q >> w;
for (int i = 1; i < n; i++) {
int a, b; ll c;
cin >> a >> b >> c;
edges[i][0] = a;
edges[i][1] = b;
edges[i][2] = c;
adj[a].push_back({b, c});
adj[b].push_back({a, c});
}
//cent(1, n);
ett(1);
for (int i = 1; i < n; i++) {
if (depth[edges[i][0]] > depth[edges[i][1]]) swap(edges[i][0], edges[i][1]);
}
seg.init(1, 1, n);
ll last = 0;
while (q--) {
int d; ll e;
cin >> d >> e;
d = (d + last) % (n - 1) + 1;
e = (e + last) % w;
int v = edges[d][1];
seg.upd(1, 1, n, in[v], out[v], e - edges[d][2]);
edges[d][2] = e;
pil x = seg.get(1, 1, n, 1, n);
pil y = seg.get(1, 1, n, 1, in[x.idx]-1);
pil z = seg.get(1, 1, n, in[x.idx]+1, n);
last = x.val + max(y.val, z.val);
cout << last << "\n";
}
return 0;
}