Submission #378164

#	Time	Username	Problem	Language	Result	Execution time	Memory
378164		arwaeystoamneg	Race (IOI11_race)	C++17	100 / 100	503 ms	75372 KiB

race

/*
ID: awesome35
LANG: C++14
TASK: vans
*/
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
#define endl '\n'
#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 998244353;//1000000007
const ld pi = 3.1415926535;

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
}
#ifndef arwaeystoamneg
#include "race.h"
#endif
int n, k;
vector<vpi>adj;
vi parent, dist, depth;
int ans = inf;
void dfs0(int i, int p)
{
	parent[i] = p;
	trav(x, adj[i])
	{
		if (x.f != p)
		{
			depth[x.f] = 1 + depth[i];
			dist[x.f] = x.s + dist[i];
			dfs0(x.f, i);
		}
	}
}
void merge(map<ll, int>& a, map<ll, int>& b, int dist, int depth)
{
	if (sz(a) < sz(b))swap(a, b);
	// merge b into a
	trav(x, b)
	{
		if (a.count(k - x.f + 2 * dist))ans = min(ans, x.s + a[k - x.f + 2 * dist] - 2 * depth);
	}
	trav(x, b)
	{
		if (a.count(x.f))a[x.f] = min(a[x.f], x.s);
		else a.insert(x);
	}
}
map<ll, int> dfs(int i, int p)
{
	map<ll, int>a, t;
	trav(x, adj[i])
	{
		if (x.f == p)continue;
		t = dfs(x.f, i);
		merge(a, t, dist[i], depth[i]);
		if (ans == 321)
			message
	}
	if (a.count(dist[i] + k))ans = min(ans, a[dist[i] + k] - depth[i]);
	if (ans == 321)
		message
	a[dist[i]] = depth[i];
	return a;
}
int best_path(int N, int K, int H[][2], int L[])
{
	n = N;
	k = K;
	adj.rsz(n);
	F0R(i, n - 1)
	{
		int x = H[i][0], y = H[i][1];
		adj[x].pb({ y,L[i] });
		adj[y].pb({ x,L[i] });
	}
	parent.rsz(n);
	dist.rsz(n);
	depth.rsz(n);
	dfs0(0, -1);
	dfs(0, -1);
	if (ans == inf)return -1;
	return ans;
}
#ifdef arwaeystoamneg
int main()
{
	setIO("");

	int n, k;
	cin >> n >> k;
	const int MAX = 2e5;
	int H[MAX][2], L[MAX];
	F0R(i, n - 1)cin >> H[i][0] >> H[i][1] >> L[i];
	cout << best_path(n, k, H, L) << endl;
}
#endif

Compilation message (stderr)

race.cpp: In function 'void setIO(std::string)':
race.cpp:53:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   53 |   freopen((s + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:55:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   55 |    freopen((s + ".out").c_str(), "w", stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 22 / 22
• Subtask 4: 57 / 57