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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#556830 | #6737. Neighbourhood | 251Sec | TL | 4ms | 34600kb | C++14 | 4.4kb | 2024-09-10 21:18:28 | 2024-09-10 21:18:28 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int B = 2000;
struct Edge {
int v, nxt;
} e[400005];
int head[200005], len = 1;
void Insert(int u, int v) {
e[++len] = { v, head[u] };
head[u] = len;
}
int n, q;
int dpt[200005], lt[200005], rt[200005], cti, st[20][200005], prt[200005];
ll we[200005];
namespace BIT {
ll f[200005];
void M(int i, ll w) { for (; i <= n; i += i & -i) f[i] += w; }
ll Q(int i) { ll res = 0; for (; i; i &= i - 1) res += f[i]; return res; }
void Modify(int u, ll w) { M(lt[u], w), M(rt[u] + 1, -w); }
ll Query(int u) { return Q(lt[u]); }
}
void DFS(int u, int fa) {
st[0][lt[u] = ++cti] = prt[u] = fa;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
if (v == fa) continue;
dpt[i >> 1] = v;
DFS(v, u);
BIT::Modify(v, we[i >> 1]);
}
rt[u] = cti;
}
int PMin(int u, int v) { return lt[u] < lt[v] ? u : v; }
void PreST() {
for (int j = 1; j < 20; j++) {
for (int i = 1; i + (1 << j) - 1 <= n; i++) {
st[j][i] = PMin(st[j - 1][i], st[j - 1][i + (1 << (j - 1))]);
}
}
}
int LCA(int u, int v) {
if (u == v) return u;
if ((u = lt[u]) > (v = lt[v])) swap(u, v);
int x = __lg(v - u++);
return PMin(st[x][u], st[x][v - (1 << x) + 1]);
}
int ubn[200005], dbn[200005];
vector<int> clu[200005], bn;
namespace TopCluster {
int ccl[200005], ccnt, st[200005], top;
void AddCl(int u, int v) {
if (!v) v = ccl[ccnt];
for (int i = 1; i <= ccnt; i++) {
int r = ccl[i];
ubn[r] = u, dbn[r] = v, clu[v].push_back(r);
}
ccnt = 0;
}
int wai[200005], rec[200005], ctp[200005];
void DFS(int u, int fa) {
ctp[u] = top, wai[u] = 1;
int bcnt = 0;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
if (v == fa) continue;
st[++top] = v;
DFS(v, u);
wai[u] += wai[v];
if (rec[v]) rec[u] = rec[v], bcnt++;
}
if (wai[u] > B || bcnt > 1 || !fa) {
wai[u] = 0, rec[u] = u;
int j = ctp[u] + 1, cnt = 0, cdn = 0;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
if (v == fa) continue;
if (cnt + wai[v] > B || (rec[v] && cdn)) {
for (; j < ctp[v] && j <= top; j++) ccl[++ccnt] = st[j];
AddCl(u, cdn), cdn = cnt = 0;
}
cnt += wai[v];
if (rec[v]) cdn = rec[v];
}
for (; j <= top; j++) ccl[++ccnt] = st[j];
if (u == 1) ccl[++ccnt] = 1;
AddCl(u, cdn);
top = ctp[u];
}
}
}
ll du[200005], dd[200005];
void ReDFS(int u, int fa, int col, ll dis, ll *a) {
if (dbn[u] == col) a[u] = dis;
else if (u != ubn[col]) return;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
if (v == fa) continue;
ReDFS(v, u, col, dis + we[i >> 1], a);
}
}
vector<int> pu[200005], pd[200005];
void Modify(int x, ll y) {
BIT::Modify(dpt[x], y - we[x]);
we[x] = y;
int b = dbn[dpt[x]], a = ubn[b];
ReDFS(a, 0, b, 0, du), ReDFS(b, 0, b, 0, dd);
sort(pu[b].begin(), pu[b].end(), [](int x, int y) {
return du[x] < du[y];
});
sort(pd[b].begin(), pd[b].end(), [](int x, int y) {
return dd[x] < dd[y];
});
}
ll D(int u, int v) {
return BIT::Query(u) + BIT::Query(v) - 2 * BIT::Query(LCA(u, v));
}
int Query(int x, ll y) {
int ans = 0;
for (auto u : clu[dbn[x]]) {
if (D(u, x) <= y) ans++;
}
for (auto u : bn) {
if (u == dbn[x]) continue;
ll da = D(ubn[u], x), db = D(u, x);
if (da < db) {
du[n + 1] = y - da;
ans += upper_bound(pu[u].begin(), pu[u].end(), n + 1, [](int x, int y) {
return du[x] < du[y];
}) - pu[u].begin();
}
else {
dd[n + 1] = y - db;
ans += upper_bound(pd[u].begin(), pd[u].end(), n + 1, [](int x, int y) {
return dd[x] < dd[y];
}) - pd[u].begin();
}
}
return ans;
}
int main() {
scanf("%d%d", &n, &q);
for (int i = 1, u, v, w; i < n; i++) {
scanf("%d%d%d", &u, &v, &w);
Insert(u, v), Insert(v, u);
we[i] = w;
}
DFS(1, 0), PreST(), TopCluster::DFS(1, 0);
for (int i = 1; i <= n; i++) {
bn.push_back(dbn[i]);
pu[i] = pd[i] = clu[i];
}
sort(bn.begin(), bn.end());
bn.erase(unique(bn.begin(), bn.end()), bn.end());
for (int x : bn) {
int b = x, a = ubn[b];
ReDFS(a, 0, b, 0, du), ReDFS(b, 0, b, 0, dd);
sort(pu[b].begin(), pu[b].end(), [](int x, int y) {
return du[x] < du[y];
});
sort(pd[b].begin(), pd[b].end(), [](int x, int y) {
return dd[x] < dd[y];
});
}
while (q--) {
int op, x, y; scanf("%d%d%d", &op, &x, &y);
if (op == 1) Modify(x, y);
else printf("%d\n", Query(x, y));
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 4ms
memory: 34600kb
input:
3 7 1 2 3 2 3 1 2 2 1 2 1 3 2 3 4 1 1 1 2 2 1 2 1 0 2 3 1
output:
2 2 3 3 1 2
result:
ok 6 numbers
Test #2:
score: -100
Time Limit Exceeded
input:
200000 200000 1 2 146181238 2 3 45037818 3 4 176924060 4 5 969365276 5 6 683948619 6 7 356268194 7 8 871634797 8 9 630254480 9 10 283061123 10 11 204904965 11 12 838381393 12 13 516373812 13 14 253862710 14 15 223572474 15 16 114452997 16 17 145251056 17 18 905638436 18 19 375445402 19 20 549829545 ...
output:
3 0 0 7 0 7 4 4 2 6 0 0 10 0 0 3 0 0 1 0 0 0 0 0 0 0 10 0 7 0 0 0 1 8 2 0 0 0 4 3 0 0 6 0 2 2 0 8 1 6 0 3 0 0 3 0 3 5 3 7 0 3 1 0 11 6 12 3 3 5 6 0 8 0 4 6 1 1 0 0 5 0 7 0 0 5 8 2 0 2 5 0 0 9 2 0 0 3 5 0 0 6 0 0 0 0 0 0 8 0 11 0 0 3 4 0 0 6 0 2 0 2 3 0 0 0 1 2 0 0 0 7 0 0 6 8 0 0 1 7 11 0 4 5 1 3 1 ...