#include<bits/stdc++.h>
#ifdef LOCAL
#include "Essentials/algo/debug.h"
#else
#define debug(...) 69
#endif
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const int N = 5e5 + 23;
const ll inf = 1e18;
#define F first
#define S second
#define pb push_back
#define kill(x) cout<<x<<endl, exit(0);
#define all(x) x.begin(),x.end()
#define sz(x) (int)x.size()
#define lc (v << 1)
#define rc ((v<<1) |1)
#define int ll
struct node {
int diam;
int leftMax;
int rightMax;
int mxh,mnh;
int lz;
void set(int h) {
diam = 0;
leftMax = -h;
rightMax = -h;
mxh = h,mnh = h;
lz = 0;
}
void merge(node a,node b) {
mxh = max(a.mxh,b.mxh);
mnh = min(a.mnh,b.mnh);
leftMax = max({a.leftMax, b.leftMax ,b.mxh - 2*a.mnh});
rightMax =max({a.rightMax,b.rightMax,a.mxh - 2*b.mnh});
diam = max({ a.diam, b.diam, a.rightMax + b.mxh , b.leftMax+ a.mxh});
}
} t[N<<2];
int n,q;
int h[N];
int st[N],ft[N];
int what[N];
void build(int v=1,int tl =0,int tr= N) {
if(tr-tl == 1) {
t[v].set(h[what[tl]]);
return;
}
int mid=(tl+tr)/2;
build(lc,tl,mid);
build(rc,mid,tr);
t[v].merge(t[lc],t[rc]);
debug(tl,tr,t[v].diam,t[v].leftMax,t[v].rightMax);
}
void shift(int v) {
int x = t[v].lz;
t[lc].leftMax -= x;
t[lc].rightMax -= x;
t[lc].mxh += x;
t[lc].mnh += x;
t[lc].lz += x;
t[rc].leftMax -= x;
t[rc].rightMax -= x;
t[rc].mxh += x;
t[rc].mnh += x;
t[rc].lz += x;
t[v].lz = 0;
}
void upd(int l,int r,int x,int v=1,int tl=0,int tr =N) {
if(l > r) return;
if(l == tl && r == tr-1) {
t[v].leftMax -= x;
t[v].rightMax -= x;
t[v].mxh += x;
t[v].mnh += x;
t[v].lz += x;
return;
}
shift(v);
int mid=(tl + tr)/2;
upd(l,min(mid-1,r),x,lc,tl,mid);
upd(max(l,mid),r,x,rc,mid,tr);
t[v].merge(t[lc],t[rc]);
}
int W;
int w[N];
int ver[N];
vector<pll> G[N];
int timer;
void dfs(int v,int p =-1) {
what[timer] = v;
st[v] = timer ++;
for(auto [u,id] : G[v]) if(u != p) {
ver[id] = u;
h[u] = h[v] + w[id];
dfs(u,v);
what[timer] = v;
ft[v]= timer ++;
}
what[timer] = v;
ft[v]= timer ++;
}
int32_t main() {
cin.tie(nullptr)->sync_with_stdio(false);
cin>>n>>q>>W;
int last= 0;
for(int i = 0; i<n-1 ; i ++) {
int v,u; cin>>v>>u>>w[i];
G[v].pb({u,i});
G[u].pb({v,i});
}
dfs(1);
build();
debug(t[1].diam);
while(q--) {
int e,d; cin>>e>>d;
e= (e + last) % (n-1);
d= (d +last) % W;
int v= ver[e];
//debug(st[v],ft[v]);
upd(st[v],ft[v]-1,-w[e]);
w[e] = d;
upd(st[v],ft[v]-1,w[e]);
last = t[1].diam;
cout<<last << '\n';
}
return 0;
}
Compilation message
diameter.cpp: In function 'void build(ll, ll, ll)':
diameter.cpp:5:20: warning: statement has no effect [-Wunused-value]
5 | #define debug(...) 69
| ^~
diameter.cpp:68:2: note: in expansion of macro 'debug'
68 | debug(tl,tr,t[v].diam,t[v].leftMax,t[v].rightMax);
| ^~~~~
diameter.cpp: In function 'int32_t main()':
diameter.cpp:5:20: warning: statement has no effect [-Wunused-value]
5 | #define debug(...) 69
| ^~
diameter.cpp:135:2: note: in expansion of macro 'debug'
135 | debug(t[1].diam);
| ^~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
19 ms |
72280 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
19 ms |
72280 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
17 ms |
72280 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
16 ms |
72536 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
183 ms |
85072 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
19 ms |
72280 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
