#ifndef hwe
#include "highway.h"
#endif
#include <bits/stdc++.h>
using namespace std;
#define popcount(n) (__builtin_popcountll((n)))
#define clz(n) (__builtin_clzll((n)))
#define ctz(n) (__builtin_ctzll((n)))
#define lg(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))
#define Int __int128
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;
template <class T1, class T2>
bool maximize(T1 &x, T2 y) {
if (x < y) {
x = y;
return true;
}
return false;
}
template <class T1, class T2>
bool minimize(T1 &x, T2 y) {
if (x > y) {
x = y;
return true;
}
return false;
}
template <class T>
void remove_duplicate(vector<T> &ve) {
sort (ve.begin(), ve.end());
ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template <class T> T random(T l, T r) {
return uniform_int_distribution<T>(l, r)(rng);
}
template <class T> T random(T r) {
return rng() % r;
}
const int N = 90000 + 5;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const ll INF = 1e18;
const int LIGHT = 0, HEAVY = 1;
int dep[N], e[N];
vii adj[N];
vector<int> ve[N];
#ifdef hwe
namespace Grader {
int n, m, s, t;
ll dist[N];
pii edges[N];
vii adj[N];
vector<int> w;
void get() {
cin >> n >> m >> s >> t;
for (int i = 0; i < m; ++i) {
int u, v; cin >> u >> v;
adj[u].emplace_back(v, i), adj[v].emplace_back(u, i);
edges[i] = make_pair(u, v);
}
}
ll dijkstra(int s, int t) {
memset(dist, 0x0f, sizeof dist); dist[s] = 0;
priority_queue<pli, vli, greater<pli>> pq; pq.emplace(0, s);
while (!pq.empty()) {
int u = pq.top().se; pq.pop();
// cerr << "dijkstra " << u << ' ' << dist[u] << '\n';
for (auto [v, id] : adj[u]) if (minimize(dist[v], dist[u] + w[id])) {
pq.emplace(dist[v], v);
}
}
return dist[t];
}
ll ask(const vector<int> &_w) {
w = _w; for (auto &x : w) ++x;
return dijkstra(s, t);
}
}
ll ask(const vector<int> &w) {
return Grader::ask(w);
}
void answer(int s, int t) {
cerr << "Answer " << s << ' ' << t << '\n';
}
#endif
void dfs(int u, int fa) {
for (auto [v, id] : adj[u]) if (v != fa) {
dep[v] = dep[u] + 1, e[v] = id;
ve[dep[v]].emplace_back(v);
dfs(v, u);
}
}
void find_pair(int n, vector<int> U, vector<int> V, int A, int B) {
int m = U.size();
for (int i = 0; i < m; ++i) {
adj[U[i]].emplace_back(V[i], i), adj[V[i]].emplace_back(U[i], i);
}
dfs(0, -1);
int low = 1, high = n - 1, depth = 0;
while (low <= high) {
int mid = low + high >> 1; vector<int> w(m, HEAVY); ll expected = 1ll * mid * A;
for (int d = 1; d <= mid; ++d) for (auto v : ve[d]) {
w[e[v]] = LIGHT;
}
// cerr << mid << ' ' << ask(w) << '\n';
if (expected <= ask(w)) low = (depth = mid) + 1;
else high = mid - 1;
}
cerr << "depth = " << depth << '\n';
for (auto &x : ve[depth]) cerr << x << ' ';
cerr << '\n';
low = 0, high = ve[depth].size() - 1; int pos = -1; ll expected = 1ll * depth * B;
while (low <= high) {
int mid = low + high >> 1; vector<int> w(m, HEAVY);
for (int i = 0; i <= mid; ++i) w[e[ve[depth][i]]] = LIGHT;
// cerr << mid << ' ' << ask(w) << '\n';
if (ask(w) < expected) high = (pos = mid) - 1;
else low = mid + 1;
}
answer(0, ve[depth][pos]);
}
#ifdef hwe
signed main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#ifdef hwe
freopen("input.inp", "r", stdin);
freopen("output.out", "w", stdout);
#else
#define taskname ""
if (fopen(taskname".inp", "r")) {
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
#endif
Grader::get();
int n = Grader::n; vector<int> U, V;
for (int i = 0; i < Grader::m; ++i) {
int u, v; tie(u, v) = Grader::edges[i];
U.emplace_back(u), V.emplace_back(v);
}
find_pair(n, U, V, 1, 2);
cerr << '\n'; return 0;
}
#endif
Compilation message
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:140:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
140 | int mid = low + high >> 1; vector<int> w(m, HEAVY); ll expected = 1ll * mid * A;
| ~~~~^~~~~~
highway.cpp:155:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
155 | int mid = low + high >> 1; vector<int> w(m, HEAVY);
| ~~~~^~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4688 KB |
Output is correct |
2 |
Correct |
1 ms |
4688 KB |
Output is correct |
3 |
Correct |
1 ms |
4688 KB |
Output is correct |
4 |
Correct |
1 ms |
4688 KB |
Output is correct |
5 |
Correct |
2 ms |
4688 KB |
Output is correct |
6 |
Correct |
2 ms |
4688 KB |
Output is correct |
7 |
Correct |
2 ms |
4688 KB |
Output is correct |
8 |
Correct |
1 ms |
4688 KB |
Output is correct |
9 |
Correct |
2 ms |
4688 KB |
Output is correct |
10 |
Correct |
2 ms |
4688 KB |
Output is correct |
11 |
Correct |
3 ms |
4688 KB |
Output is correct |
12 |
Correct |
1 ms |
4688 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4688 KB |
Output is correct |
2 |
Correct |
14 ms |
5200 KB |
Output is correct |
3 |
Correct |
127 ms |
11084 KB |
Output is correct |
4 |
Correct |
123 ms |
11648 KB |
Output is correct |
5 |
Correct |
121 ms |
11096 KB |
Output is correct |
6 |
Correct |
109 ms |
11028 KB |
Output is correct |
7 |
Correct |
125 ms |
11084 KB |
Output is correct |
8 |
Correct |
123 ms |
11176 KB |
Output is correct |
9 |
Correct |
94 ms |
11096 KB |
Output is correct |
10 |
Correct |
122 ms |
11096 KB |
Output is correct |
11 |
Correct |
105 ms |
12872 KB |
Output is correct |
12 |
Correct |
97 ms |
14132 KB |
Output is correct |
13 |
Correct |
95 ms |
13152 KB |
Output is correct |
14 |
Correct |
94 ms |
12164 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
6348 KB |
Output is incorrect: {s, t} is wrong. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
4688 KB |
Output is incorrect: {s, t} is wrong. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
63 ms |
33328 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
60 ms |
33344 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |