#include<bits/stdc++.h>
using namespace std;
// consideram initial ca toate distantele sunt 0 si apoi updatam cu costul muchiilor
const int N = 100005;
const int LOGN = 18;
// aint
long long aint[N * LOGN * 4 + 5];
long long lazy[N * LOGN * 4 + 5];
void propag(int nod, int l, int r){
aint[nod] += 1LL * lazy[nod];
if(l != r){
lazy[2*nod] += lazy[nod];
lazy[2*nod + 1] += lazy[nod];
}
lazy[nod] = 0;
}
void update(int nod, int l, int r, int ul, int ur, long long val){
propag(nod, l, r);
if(ur < l || r < ul)
return;
if(ul <= l && r <= ur){
lazy[nod] += val;
propag(nod, l, r);
return;
}
int mid = (l + r)/2;
update(2*nod, l, mid, ul, ur, val);
update(2*nod + 1, mid + 1, r, ul, ur, val);
aint[nod] = max(aint[2*nod], aint[2*nod + 1]);
}
long long query(int nod, int l, int r, int ql, int qr){
propag(nod, l, r);
if(r < ql || qr < l)
return 0;
if(ql <= l && r <= qr)
return aint[nod];
int mid = (l + r)/2;
long long ls = query(2*nod, l, mid, ql, qr);
long long rs = query(2*nod + 1, mid + 1, r, ql, qr);
return max(ls, rs);
}
vector<int> gr[N];
int croot[LOGN][N];
int fson[LOGN][N];
int in[LOGN][N];
int out[LOGN][N];
bool wasC[N];
int sz[N];
void dfs_sz(int nod, int dad){
sz[nod] = 1;
for(auto x:gr[nod]){
if(x!= dad && wasC[x] == false){
dfs_sz(x, nod);
sz[nod] += sz[x];
}
}
}
int find_centro(int nod, int dad, int bound){
for(auto x:gr[nod]){
if(wasC[x] == false && x!= dad && sz[x] > bound)
return find_centro(x, nod, bound);
}
return nod;
}
void dfs_from_centro(int nod, int dad, int cnumber, int &id, int centro, int fs){
if(dad == centro)
fs = nod;
croot[cnumber][nod] = centro;
fson[cnumber][nod] = fs;
in[cnumber][nod] = ++id;
for(auto x:gr[nod]){
if(x != dad && wasC[x] == false){
dfs_from_centro(x, nod, cnumber, id, centro, fs);
}
}
out[cnumber][nod] = id;
}
priority_queue<pair<long long, pair<int, int>>> best[N];
long long cval[LOGN][N];
long long bs[N];
priority_queue<pair<long long, int>> bsum;
void centro_dec(int nod, int number, int &id){
dfs_sz(nod, 0);
int sze = sz[nod];
int centro = find_centro(nod, 0, sze / 2);
dfs_from_centro(centro, 0, number, id, centro, centro);
for(auto x:gr[centro]){
if(wasC[x] == false){
best[centro].push({0, {number, centro}});
}
}
bs[centro] = 0;
bsum.push({bs[centro], centro});
wasC[centro] = true;
for(auto x:gr[centro]){
if(wasC[x] == false)
centro_dec(x, number + 1, id);
}
}
int L, R;
long long sumbig2(priority_queue<pair<long long, pair<int, int>>> best){
long long sum =0;
while(best.size() && cval[best.top().second.first][best.top().second.second] != best.top().first)
best.pop();
if(best.empty())
return sum;
sum += best.top().first;
auto mx = best.top();
best.pop();
while(best.size() && cval[best.top().second.first][best.top().second.second] != best.top().first)
best.pop();
if(best.empty()){
best.push(mx);
return sum;
}
sum += best.top().first;
best.push(mx);
return sum;
}
bool isdad(int number, int dad, int son){
if(in[number][dad] <= in[number][son] && out[number][son] <= out[number][dad])
return true;
return false;
}
void update_edge(int nod, int onod, long long change){
int number = 0;
for(; number < LOGN; number++){
if(croot[number][nod] == nod)
break;
}
while(number > 0 && croot[number][nod] != croot[number][onod])
number--;
for(; number >= 0; number--){
if(isdad(number, nod, onod) == true)
swap(nod, onod);
int centro = croot[number][nod];
int fs = fson[number][nod];
long long old_big = cval[number][fs];
update(1, L, R, in[number][nod], out[number][nod], change);
long long new_big = query(1, L, R, in[number][fs], out[number][fs]);
cval[number][fs] = new_big;
best[centro].push({new_big, {number, fs}});
long long nsum = sumbig2(best[centro]);
bs[centro] = nsum;
bsum.push({nsum, centro});
}
}
struct edges{
int x, y;
long long c;
};
int main()
{
//freopen(".in","r",stdin);
ios::sync_with_stdio(false);
cin.tie(0),cout.tie(0);
int n, q;
long long w;
cin>>n>>q>>w;
vector<edges> es;
for(int i = 0; i < n - 1; i++){
int x, y, c;
cin>>x>>y>>c;
es.push_back({x, y, c});
gr[x].push_back(y);
gr[y].push_back(x);
}
centro_dec(1, 0, R);
L = 1;
for(int i = 0; i < n - 1; i++){
update_edge(es[i].x, es[i].y, es[i].c);
}
long long last = 0;
for(int i = 1; i<=q; i++){
long long d, e;
cin>>d>>e;
d = (last + d)%(n - 1);
e = (last + e)% w;
long long df = e - es[d].c;
update_edge(es[d].x, es[d].y, df);
es[d].c = e;
while(bsum.size() && bs[bsum.top().second] != bsum.top().first)
bsum.pop();
last = bsum.top().first;
cout<<last<<"\n";
}
return 0;
}
Compilation message
diameter.cpp: In function 'void update_edge(int, int, long long int)':
diameter.cpp:144:15: warning: unused variable 'old_big' [-Wunused-variable]
144 | long long old_big = cval[number][fs];
| ^~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
5964 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
5964 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
5836 KB |
Output is correct |
| 2 |
Correct |
6 ms |
5836 KB |
Output is correct |
| 3 |
Incorrect |
32 ms |
5980 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
24 ms |
7108 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
5031 ms |
9280 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
5964 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
