/* Author : Mychecksdead */
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD1 (1000000000+7)
#define MOD (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;
int n, q;
bool case3 = 1, case4 = 1;
pair<int, ll> par[N];
ll w, dp[N];
vector<int> g[N];
vector<pair<int, ll>> edges(N);
multiset<ll> s, dps[N], answers;
ll f(multiset<ll> &a){
if(a.empty()) return 0;
if(a.size() == 1) return *(a.begin());
auto it = a.end(); --it;
ll x = *it; --it; x += *it;
return x;
}
ll dfs(int v, int p){
pair<ll, ll> best = {0, 0};
dp[v] = 0;
ll d = 0;
for(int E: g[v]){
auto e = edges[E];
int u = e.first;
if(u == p) continue;
d = max(d, dfs(u, v));
par[u] = {v, e.second};
dp[v] = max(dp[v], dp[u] + e.second);
if(best.first < dp[u] + e.second){
swap(best.first, best.second);
best.first = dp[u] + e.second;
}else if(best.second < dp[u] + e.second){
best.second = dp[u] + e.second;
}
if(case4)
dps[v].insert(dp[u] + e.second);
}
if(case4)
answers.insert(best.first + best.second);
return max(d, best.first + best.second);
}
void solve(){
cin >> n >> q >> w;
assert(0);
for(int i = 0; i < n - 1; ++i){
int u, v; ll x; cin >> u >> v >> x;
g[u].pb(2*i);
g[v].pb(2*i+1);
if(u != 1 && v != 1) case3 = 0;
if(v/2 != u && u/2 != v) case4 = 0;
s.insert(x);
edges[i*2] = {v, x};
edges[i*2+1] = {u, x};
}
if(case4) dfs(1, 0);
ll last = 0;
for(;q--;){
ll d, x; cin >> d >> x;
d = (d + last) % (n-1);
x = (x + last) % w;
ll old_x = edges[2*d].second;
edges[2*d].second = edges[2*d+1].second = x;
if(case3){
s.erase(s.find(old_x));
s.insert(x);
auto it = s.end(); --it;
if(s.size()==1) last = *it;
else{
last = *it;
it--;
last += *it;
}
}else if(case4){
int v = edges[2*d].first;
if(par[v].first != edges[2*d+1].first) v = edges[2*d].first;
ll cur = 0, delta = x - old_x;
if(dps[v].size() > 0) cur = *(--dps[v].end());
par[v].second = x;
while(v != 1){
cur += par[v].second;
v = par[v].first;
answers.erase(answers.find(f(dps[v])));
dps[v].erase(dps[v].find(cur - delta));
dps[v].insert(cur);
answers.insert(f(dps[v]));
}
last = *(--answers.end());
}else{
// answers.clear();
last = dfs(1, 0);
// last = *(--answers.end());
}
cout << last << '\n';
}
}
int main(){
cin.tie(0); ios::sync_with_stdio(0);
int T = 1, aa;
// cin >> T;aa=T;
while(T--){
// cout << "Case #" << aa-T << ": ";
solve();
cout << '\n';
}
return 0;
}
Compilation message
diameter.cpp: In function 'int main()':
diameter.cpp:137:16: warning: unused variable 'aa' [-Wunused-variable]
137 | int T = 1, aa;
| ^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
110 ms |
175004 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
110 ms |
175004 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
112 ms |
175004 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
110 ms |
175076 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
121 ms |
175000 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
110 ms |
175004 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
