#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
using Edge = pair<ll, pll>;
#define fi first
#define se second
const int maxN = 1e5 + 5;
const ll INF = 1e18;
ll n, q, w;
set<pll> adj[maxN];
vector<Edge> edges;
ll dist[maxN], initDia[maxN], parent[maxN];
ll timer, tin[maxN], tout[maxN], byTin[maxN];
struct Segtree {
ll sz;
vector<ll> seg, lazy;
Segtree(ll sz) : sz(sz) {
seg = lazy = vector<ll>((sz << 2) + 1, 0);
}
void build(ll pos, ll l, ll r) {
if (l > r) {return;}
if (l == r) {
seg[pos] = dist[byTin[l]];
cerr << pos << ' ' << l << ' ' << byTin[l] << ' ' << dist[byTin[l]] << '\n';
return;
}
ll m = (l+r) >> 1, lc = pos << 1, rc = lc | 1;
build(lc, l, m);
build(rc, m+1, r);
seg[pos] = max(seg[lc], seg[rc]);
}
void build() {build(1, 1, sz);}
void updateNode(ll pos, ll val) {
seg[pos] += val;
lazy[pos] += val;
}
void checkLazy(ll pos) {
if (lazy[pos] != 0) {
ll lc = pos << 1, rc = lc | 1;
updateNode(lc, lazy[pos]);
updateNode(rc, lazy[pos]);
lazy[pos] = 0;
}
}
void update(ll pos, ll l, ll r, ll ul, ll ur, ll val) {
if (l > r || ul > ur || l > ur || ul > r) return;
if (ul <= l && r <= ur) {updateNode(pos, val); return;}
checkLazy(pos);
ll m = (l+r) >> 1, lc = pos << 1, rc = lc | 1;
update(lc, l, m, ul, ur, val);
update(rc, m+1, r, ul, ur, val);
seg[pos] = max(seg[lc], seg[rc]);
}
void update(ll ul, ll ur, ll val) {update(1, 1, sz, ul, ur, val);}
ll query(ll pos, ll l, ll r, ll ul, ll ur) {
if (l > r || ul > ur || l > ur || ul > r) return 0;
if (ul <= l && r <= ur) return seg[pos];
checkLazy(pos);
ll m = (l+r) >> 1, lc = pos << 1, rc = lc | 1;
return max(query(lc, l, m, ul, ur), query(rc, m+1, r, ul, ur));
}
ll query(ll ul, ll ur) {return query(1, 1, sz, ul, ur);}
void print() {
for (ll i = 1; i <= sz; i++) {
cout << query(i, i) << ' ';
}
cout << '\n';
}
} S(1), T(1);
void compute(ll cur) {
ll cdist = S.query(tin[cur], tin[cur]);
vector<ll> children(2, cdist);
for (auto &[nxt, w] : adj[cur]) {
children.push_back(S.query(tin[nxt], tout[nxt]));
}
sort(children.begin(), children.end());
reverse(children.begin(), children.end());
//for (auto i : children) {cout << i << ' ';} cout <<'\n';
//cout << cur << ' ' << -T.query(cur, cur) + children[0] + children[1] - 2ll*cdist << '\n';
T.update(cur, cur, -T.query(cur, cur) + children[0] + children[1] - 2ll*cdist);
}
#define debug(x) cout << #x << " = " << x << '\n'
void dfs(ll cur, ll par, ll cdist, ll pw) {
//debug(cur);
tin[cur] = ++timer;
byTin[timer] = cur;
parent[cur] = par;
dist[cur] = cdist;
S.update(tin[cur], tin[cur], cdist);
adj[cur].erase({par, pw});
for (auto &[nxt, w] : adj[cur]) {
if (nxt == par) continue;
dfs(nxt, cur, cdist+w, w);
}
compute(cur);
tout[cur] = timer;
}
int main() {
scanf("%lld %lld %lld", &n, &q, &w);
for (ll a, b, c, i = 1; i < n; i++) {
scanf("%lld %lld %lld", &a, &b, &c);
adj[a].insert({b, c});
adj[b].insert({a, c});
edges.push_back({c, {a, b}});
}
S = T = Segtree(n);
dfs(1, 0, 0, 0);
for (auto &[w, p] : edges) {
if (tin[p.fi] > tin[p.se]) {swap(p.fi, p.se);}
}
//S.print(); T.print();
ll last = 0;
for (ll d, e, i = 1; i <= q; i++) {
scanf("%lld %lld", &d, &e);
d = (d + last) % (n - 1);
e = (e + last) % w;
//debug(d); debug(e);
auto &[w, p] = edges[d];
S.update(tin[p.se], tout[p.se], e-w);
adj[p.fi].erase({p.se, w});
adj[p.se].erase({p.fi, w});
edges[d].fi = e;
adj[p.fi].insert({p.se, e});
adj[p.se].insert({p.fi, e});
/*
for (ll i = 1; i <= n; i++) {
cout << i << ": ";
for (auto &[j, k] : adj[i]) {
cout << "{" << j << ", " << k << "} ";
}
cout << '\n';
}
*/
for (ll cur = p.fi; cur > 0; cur = parent[cur]) {
//debug(cur);
compute(cur);
}
//S.print(); T.print();
last = T.query(1, n);
printf("%lld\n", last);
}
}
Compilation message
diameter.cpp: In function 'int main()':
diameter.cpp:130:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
130 | scanf("%lld %lld %lld", &n, &q, &w);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diameter.cpp:132:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
132 | scanf("%lld %lld %lld", &a, &b, &c);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diameter.cpp:151:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
151 | scanf("%lld %lld", &d, &e);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4948 KB |
Output is correct |
2 |
Correct |
4 ms |
4948 KB |
Output is correct |
3 |
Correct |
8 ms |
5032 KB |
Output is correct |
4 |
Correct |
48 ms |
5076 KB |
Output is correct |
5 |
Correct |
185 ms |
5392 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
4 ms |
5076 KB |
Output is correct |
8 |
Correct |
18 ms |
5076 KB |
Output is correct |
9 |
Correct |
132 ms |
5076 KB |
Output is correct |
10 |
Correct |
1157 ms |
5464 KB |
Output is correct |
11 |
Execution timed out |
5044 ms |
5648 KB |
Time limit exceeded |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
10 ms |
5332 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
5044 ms |
36900 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |