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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#201772 | #5148. Tree Distance | luyiming123 | WA | 2225ms | 170344kb | C++14 | 5.3kb | 2023-10-05 16:42:02 | 2023-10-05 16:42:02 |
Judging History
answer
# include <bits/stdc++.h>
using namespace std;
using i64 = long long;
const int N = 2e5 + 5;
int n;
struct edge
{
int v, w; bool del;
};
struct node
{
int u, v; i64 w;
node() {}
node(int _u, int _v, i64 _w) : u(_u), v(_v), w(_w) {}
}Eg; int sizS = 0, mindelt = 1e9;
struct Query
{
int l, id;
};
vector <Query> Q[N];
bool compare(const struct node &x, const struct node &y)
{
return x.v < y.v;
}
vector <node> Pts;
vector <edge> g[N];
vector<pair<i64, int> > L, R;
int siz[N];
void find_rt(int x, int fa)
{
siz[x] = 1;
for(auto I : g[x])
{
int v = I.v;
if(v == fa || I.del) continue;
find_rt(v, x);
siz[x] += siz[v];
int dt = abs(siz[v] - (sizS - siz[v]));
if(dt < mindelt) mindelt = dt, Eg = {x, v, I.w};
}
return;
}
void dfs(int x, int fa, i64 DIST, vector <pair <i64,int> > &A)
{
A.push_back({DIST, x});
for(auto I : g[x])
{
int v = I.v;
if(v == fa || I.del) continue;
dfs(v, x, DIST + 1ll * I.w, A);
}
return;
}
void solve(node Ed)
{
// printf("solve : (%d,%d,%lld)\n", Ed.u, Ed.v, Ed.w);
for(auto &I : g[Ed.u]) if(I.v == Ed.v) {I.del = 1; break;}
for(auto &I : g[Ed.v]) if(I.v == Ed.u) {I.del = 1; break;}
L.clear(), R.clear();
set <pair<int, i64> > St;
dfs(Ed.u, Ed.v, 0, L);
dfs(Ed.v, Ed.u, 0, R);
sort(L.begin(), L.end()), sort(R.begin(), R.end());
for(int i = 0, j = 0; i < (int)L.size(); i++)
{
while(j < (int)R.size() && R[j].first <= L[i].first) St.insert({R[j].second, R[j].first}), ++j;
auto it = St.upper_bound({L[i].second, 0});
if(it != St.end()) Pts.push_back({L[i].second, (*it).first, (*it).second + L[i].first + Ed.w});
if(it != St.begin())
{
--it;
Pts.push_back({(*it).first, L[i].second, (*it).second + L[i].first + Ed.w});
}
}
St.clear();
for(int i = 0, j = 0; i < (int)R.size(); i++)
{
while(j < (int)L.size() && L[j].first <= R[i].first) St.insert({L[j].second, L[j].first}), ++j;
auto it = St.upper_bound({R[i].second, 0});
if(it != St.end()) Pts.push_back({R[i].second, (*it).first, (*it).second + R[i].first + Ed.w});
if(it != St.begin())
{
--it;
Pts.push_back({(*it).first, R[i].second, (*it).second + R[i].first + Ed.w});
}
}
int lstR = (int)R.size();
Eg = {-1, -1, -1}, sizS = (int)L.size(), mindelt = 1e9;
if(sizS >= 2) find_rt(Ed.u, Ed.v), solve(Eg);
Eg = {-1, -1, -1}, sizS = lstR, mindelt = 1e9;
if(sizS >= 2) find_rt(Ed.v, Ed.u), solve(Eg);
return;
}
struct SgT
{
struct node
{
i64 Max, tag;
}T[N << 2];
void build(int root, int l, int r)
{
T[root].Max = 1e15, T[root].tag = -1;
if(l == r) return;
int mid = (l + r) >> 1;
build(root << 1, l, mid), build(root << 1 | 1, mid + 1, r);
return;
}
void pushup(int root)
{
T[root].Max = max(T[root << 1].Max, T[root << 1 | 1].Max);
return;
}
void pushdown(int root)
{
if(T[root].tag == -1) return;
i64 tag = T[root].tag; T[root].tag = -1;
T[root << 1].Max = tag;
T[root << 1].tag = tag;
T[root << 1 | 1].Max = tag;
T[root << 1 | 1].tag = tag;
return;
}
void update(int root, int l, int r, int s, int t, i64 d)
{
if(l <= s && t <= r)
{
T[root].Max = T[root].tag = d; return;
}
pushdown(root);
int mid = (s + t) >> 1;
if(l <= mid) update(root << 1, l, r, s, mid, d);
if(r > mid) update(root << 1 | 1, l, r, mid + 1, t, d);
pushup(root);
return;
}
int query(int root, int l, int r, i64 d) // the Max x that ax > d
{
// printf("root = %d, l = %d, r = %d, d = %lld\n", root, l, r, d);
if(l == r)
{
return T[root].Max <= d ? -1 : l;
}
pushdown(root);
int mid = (l + r) >> 1;
// printf("lfMax = %lld\n", T[root << 1].Max);
return T[root << 1].Max <= d ? query(root << 1 | 1, mid + 1, r, d) : query(root << 1, l, mid, d);
}
i64 query2(int root, int l, int r, int x)
{
if(l == r) return T[root].Max;
pushdown(root);
int mid = (l + r) >> 1;
return (x <= mid) ? query2(root << 1, l, mid, x) : query2(root << 1 | 1, mid + 1, r, x);
}
void modify(int l, i64 d)
{
// printf("modify : l = %d, d = %lld\n", l, d);
// [1, l] Max(d, ai)
int pos = query(1, 1, n, d);
// printf("pos = %d\n", pos);
if(pos == -1 || pos > l) return;
update(1, pos, l, 1, n, d);
// printf("update : %d, %d, %lld\n", pos, l, d);
return;
}
}T;
i64 Ans[N];
int main(void)
{
// freopen("in.in", "r", stdin); freopen("out.out", "w", stdout);
scanf("%d", &n);
for(int i = 1; i < n; i++)
{
int u, v, w; scanf("%d%d%d", &u, &v, &w);
g[u].push_back({v, w, 0}), g[v].push_back({u, w, 0});
}
Eg = {-1, -1, -1}, mindelt = 1e9, sizS = n; find_rt(1, 0); solve(Eg);
for(auto &I : Pts) if(I.u > I.v) swap(I.u, I.v);
sort(Pts.begin(), Pts.end(), compare);
// printf("DEBUG Pts\n");
// for(auto I : Pts)
// {
// printf("%d %d %lld\n", I.u, I.v, I.w);
// }
int Test; scanf("%d", &Test);
for(int i = 1; i <= Test; i++)
{
int l, r; scanf("%d%d", &l, &r);
if(l != r) Q[r].push_back({l, i});
else Ans[i] = -1;
}
T.build(1, 1, n);
for(int r = 1, j = 0; r <= n; r++)
{
// printf("r = %d\n", r);
while(j < (int)Pts.size() && Pts[j].v == r) T.modify(Pts[j].u, Pts[j].w), ++j;
for(auto I : Q[r])
{
Ans[I.id] = T.query2(1, 1, n, I.l);
}
}
for(int i = 1; i <= Test; i++) printf("%lld\n", Ans[i]);
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 3ms
memory: 17500kb
input:
5 1 2 5 1 3 3 1 4 4 3 5 2 5 1 1 1 4 2 4 3 4 2 5
output:
-1 3 7 7 2
result:
ok 5 number(s): "-1 3 7 7 2"
Test #2:
score: -100
Wrong Answer
time: 2225ms
memory: 170344kb
input:
199999 31581 23211 322548833 176307 196803 690953895 34430 82902 340232856 36716 77480 466375266 7512 88480 197594480 95680 61864 679567992 19572 14126 599247796 188006 110716 817477802 160165 184035 722372640 23173 188594 490365246 54801 56250 304741654 10103 45884 643490340 127469 154479 214399361...
output:
59781685 1178569098929 1310877 1310877 1310877 92126 4366 92126 328055210 55721881562 4366 983605 92126 92126 1310877 92126 8212187 92126 2681285 901653 1310877 1310877 1310877 10272586 92126 784309 8367049186 10272586 4366 4366 92126 4366 4366 92126 1310877 92126 901653 4366 -1 -1 16211870 21085 43...
result:
wrong answer 1st numbers differ - expected: '29573323', found: '59781685'