#include <bits/stdc++.h>
using namespace std;
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define sp " "
#define endl "\n"
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 300005
#define L(node) node * 2
#define R(node) node * 2 + 1
#define int long long
const int INF = 2e18 + 7;
int edge[N], ind[N], tin[N], tout[N], rev[N], dist[N], cntr = 1;
vector<pii> adj[N];
int tree[2][4 * N], lazy[4 * N];
void push(int node, int l, int r){
tree[0][node] += lazy[node];
tree[1][node] += lazy[node];
if (l != r){
lazy[L(node)] += lazy[node];
lazy[R(node)] += lazy[node];
}
lazy[node] = 0;
}
void update(int node, int l, int r, int sl, int sr, int val){
push(node, l, r);
if (l > sr || r < sl) return;
if (l >= sl && r <= sr){
lazy[node] += val;
push(node, l, r);
return;
}
int mid = (l + r) / 2;
update(L(node), l, mid, sl, sr, val);
update(R(node), mid + 1, r, sl, sr, val);
for (int i = 0; i < 2; i++)
tree[i][node] = min(tree[i][L(node)], tree[i][R(node)]);
}
void build(int node, int l, int r){
if (l == r){
tree[0][node] = dist[rev[l]];
tree[1][node] = INF;
return;
}
int mid = (l + r) / 2;
build(L(node), l, mid);
build(R(node), mid + 1, r);
for (int i = 0; i < 2; i++)
tree[i][node] = min(tree[i][L(node)], tree[i][R(node)]);
}
void sett(int node, int l, int r, int sl){
push(node, l, r);
if (l > sl || r < sl) return;
if (l == r){
if (tree[1][node] >= INF) tree[1][node] = tree[0][node];
else tree[1][node] = INF;
return;
}
int mid = (l + r) / 2;
sett(L(node), l, mid, sl);
sett(R(node), mid + 1, r, sl);
for (int i = 0; i < 2; i++)
tree[i][node] = min(tree[i][L(node)], tree[i][R(node)]);
}
int query(int node, int l, int r, int sl, int sr){
push(node, l, r);
if (l > sr || r < sl) return INF;
if (l >= sl && r <= sr) return tree[1][node];
int mid = (l + r) / 2;
return min(query(L(node), l, mid, sl, sr), query(R(node), mid + 1, r, sl, sr));
}
void dfs(int node, int root, int d){
tin[node] = ind[node] = cntr;
rev[cntr] = node;
dist[node] = d;
cntr++;
for (auto i : adj[node]){
int curr = i.st, w = edge[i.nd];
if (curr != root) dfs(curr, node, d + w);
}
tout[node] = cntr;
}
int32_t main(){
//fileio();
fastio();
int n, q;
cin>>n>>q;
map<pii, int> e;
for (int i = 1; i < n; i++){
int u, v, w;
cin>>u>>v>>w;
adj[u].pb({v, i});
adj[v].pb({u, i});
e[{u, v}] = e[{v, u}] = i;
edge[i] = w;
}
dfs(1, 0, 0);
build(1, 1, n);
set<int> grape;
while(q--){
int t;
cin>>t;
if (t == 1){
int x;
cin>>x;
int ans = query(1, 1, n, 1, n);
if (ans < INF) cout<<ans<<endl;
else cout<<-1<<endl;
}
else if (t == 2){
int x;
cin>>x;
sett(1, 1, n, ind[x]);
}
else{
int a, b, w;
cin>>a>>b>>w;
int ee = e[{a, b}];
int diff = w - edge[ee];
edge[ee] = w;
if (tin[a] > tin[b]) swap(a, b);
update(1, 1, n, tin[b], tout[b] - 1, diff);
}
}
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
25436 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
221 ms |
49780 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
137 ms |
49904 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
195 ms |
49492 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
223 ms |
50004 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
25436 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
