| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 776481 |
2023-07-08T02:07:14 Z |
horiiseun |
Network (BOI15_net) |
C++17 |
|
2 ms |
2644 KB |
#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <cmath>
#include <random>
#include <string>
#include <bitset>
#include <cassert>
#include <climits>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
using namespace std;
#define ll long long
#define f first
#define s second
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template<typename A> void __print(const A &x);
template<typename A, typename B> void __print(const pair<A, B> &p);
template<typename... A> void __print(const tuple<A...> &t);
template<typename T> void __print(stack<T> s);
template<typename T> void __print(queue<T> q);
template<typename T, typename... U> void __print(priority_queue<T, U...> q);
template<typename A> void __print(const A &x) {
bool first = true;
cerr << '{';
for (const auto &i : x) {
cerr << (first ? "" : ","), __print(i);
first = false;
}
cerr << '}';
}
template<typename A, typename B> void __print(const pair<A, B> &p) {
cerr << '(';
__print(p.f);
cerr << ',';
__print(p.s);
cerr << ')';
}
template<typename... A> void __print(const tuple<A...> &t) {
bool first = true;
cerr << '(';
apply([&first] (const auto &...args) { ((cerr << (first ? "" : ","), __print(args), first = false), ...); }, t);
cerr << ')';
}
template<typename T> void __print(stack<T> s) {
vector<T> debugVector;
while (!s.empty()) {
T t = s.top();
debugVector.push_back(t);
s.pop();
}
reverse(debugVector.begin(), debugVector.end());
__print(debugVector);
}
template<typename T> void __print(queue<T> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.front();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
template<typename T, typename... U> void __print(priority_queue<T, U...> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.top();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
void _print() { cerr << "]\n"; }
template <typename Head, typename... Tail> void _print(const Head &H, const Tail &...T) {
__print(H);
if (sizeof...(T)) cerr << ", ";
_print(T...);
}
#ifdef DEBUG
#define D(...) cerr << "Line: " << __LINE__ << " [" << #__VA_ARGS__ << "] = ["; _print(__VA_ARGS__)
#else
#define D(...)
#endif
int n, deg[100005], rt, idx, in[100005];
bool seen[100005];
vector<int> adj[100005];
vector<pair<int, int>> leaf, ret;
void dfs(int curr, int par) {
in[curr]++;
for (int i : adj[curr]) {
if (i == par) continue;
dfs(i, curr);
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n;
for (int i = 0, a, b; i < n - 1; i++) {
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
deg[a]++;
deg[b]++;
}
for (int i = 1; i <= n; i++) {
if (deg[i] > 1) {
rt = i;
break;
}
}
dfs(rt, -1);
for (int i = 1; i <= n; i++) {
if (deg[i] == 1) {
leaf.push_back({in[i], i});
}
}
sort(leaf.begin(), leaf.end());
for (int i = 0; i < leaf.size() - 2; i++) {
if (i <= leaf.size() - 3 && !seen[i]) {
seen[i] = true;
seen[i + 2] = true;
ret.push_back({leaf[i].s, leaf[i + 2].s});
}
}
if (leaf.size() % 2) ret.push_back({leaf.back().s, leaf[0].s});
cout << ret.size() << "\n";
for (auto [a, b] : ret) {
cout << a << " " << b << "\n";
}
}
Compilation message
net.cpp: In function 'int main()':
net.cpp:157:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
157 | for (int i = 0; i < leaf.size() - 2; i++) {
| ~~^~~~~~~~~~~~~~~~~
net.cpp:158:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
158 | if (i <= leaf.size() - 3 && !seen[i]) {
| ~~^~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2644 KB |
Invalid number of links. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2644 KB |
Invalid number of links. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2644 KB |
Invalid number of links. |
| 2 |
Halted |
0 ms |
0 KB |
- |
