#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
using namespace std;
void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5 + 100, mxc = 105, inf = 1e18, MX = 1e5 + 10;
set <pair <int,int> > g[N];
int t[N * 4][2];
int tx[N * 4];
int di[N * 4];
void update(int v){
tx[v] = max(t[v * 2][0] + t[v * 2][1], t[v * 2 + 1][0] + t[v * 2 + 1][1]);
tx[v] = max({tx[v], tx[v * 2], tx[v * 2 + 1]});
if(v == 1)return;
int par = v / 2;
t[par][v & 1] = max(t[v][0], t[v][1]) + di[v];
update(par);
}
int res=0,mx=0,va;
void dfs(int v,int par = -1,int dis = 0){
if(dis>mx){
mx=dis;
va=v;
}
for(auto to:g[v]){
if(to.ss==par){
continue;
}
dfs(to.ss,v,dis+to.ff);
}
}
main(){
iostream::sync_with_stdio (false);
cin.tie(nullptr);
cout.tie(nullptr);
int n, q, W;
cin >> n >> q >> W;
vector <array<int, 3> > vp(n);
set <pair <int,int> > st;
for(int i = 0; i < n - 1; i++){
int a, b, c;
cin >> a >> b >> c;
g[a].insert({c, b});
g[b].insert({c, a});
di[b] = c;
st.insert({c, b});
vp[i] = {a, b, c};
}
for(int i = n; i >= 1; i--){
update(i);
}
int last = 0;
while(q--){
int d, e;
cin >> d >> e;
d = (d + last) % (n - 1);
e = (e + last) % W;
auto &[a, b, c] = vp[d];
g[a].erase({c, b});
g[b].erase({c, a});
st.erase({c, b});
di[b] = e;
g[a].insert({e, b});
g[b].insert({e, a});
vp[d][2] = e;
if(b / 2 != a)return EXIT_FAILURE;
update(b);
cout << max(tx[1], t[1][1] + t[1][0]) << endl;
last = max(tx[1], t[1][1] + t[1][0]);
//cout <<"ind"<< last % (n - 1)<< endl;
/*else{
dfs(1);
dfs(va);
cout << mx << endl;
last = mx;
mx = -inf;
}
*/
}
}
/*
* Before implementing the problem:
Do I understand the problem correctly?
Which places are tricky? What do I need to remember to implement them correctly?
Which place is the heaviest by implementation? Can I do it simpler?
Which place is the slowest? Where do I need to be careful about constant factors and where I can choose slower but simpler implementation?
----------------------------------
If not AC:
Did you remember to do everything to handle the tricky places you thought about before?
Is the solution correct?
Do I understand the problem correctly?
----------------------------------
If you have a test on which the solution gives wrong answer:
Is the solution doing what it was supposed to do?
Is the problem in the code or in the idea?
*/
Compilation message
diameter.cpp:52:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
52 | main(){
| ^~~~
diameter.cpp: In function 'void fp(std::string)':
diameter.cpp:15:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
15 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diameter.cpp:15:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
15 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
2 ms |
7260 KB |
Execution failed because the return code was nonzero |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
2 ms |
7260 KB |
Execution failed because the return code was nonzero |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
2 ms |
7256 KB |
Execution failed because the return code was nonzero |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
7516 KB |
Output is correct |
| 2 |
Correct |
22 ms |
8048 KB |
Output is correct |
| 3 |
Correct |
77 ms |
7636 KB |
Output is correct |
| 4 |
Correct |
150 ms |
7992 KB |
Output is correct |
| 5 |
Correct |
10 ms |
11364 KB |
Output is correct |
| 6 |
Correct |
25 ms |
11612 KB |
Output is correct |
| 7 |
Correct |
92 ms |
11784 KB |
Output is correct |
| 8 |
Correct |
170 ms |
13140 KB |
Output is correct |
| 9 |
Correct |
50 ms |
23380 KB |
Output is correct |
| 10 |
Correct |
70 ms |
23356 KB |
Output is correct |
| 11 |
Correct |
147 ms |
24012 KB |
Output is correct |
| 12 |
Correct |
232 ms |
24764 KB |
Output is correct |
| 13 |
Correct |
99 ms |
32848 KB |
Output is correct |
| 14 |
Correct |
117 ms |
33104 KB |
Output is correct |
| 15 |
Correct |
199 ms |
33608 KB |
Output is correct |
| 16 |
Correct |
415 ms |
34632 KB |
Output is correct |
| 17 |
Correct |
294 ms |
34188 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
124 ms |
31200 KB |
Execution failed because the return code was nonzero |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
2 ms |
7260 KB |
Execution failed because the return code was nonzero |
| 2 |
Halted |
0 ms |
0 KB |
- |
