Submission #1165028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1165028		Nonoze	Tug of War (BOI15_tug)	C++20	100 / 100	277 ms	15444 KiB

tug

/*
*	Author: Nonoze
*	Created: Friday 07/03/2025
*/
#include <bits/stdc++.h>
using namespace std;

#ifndef DEBUG
	#define dbg(...)
#endif

// #define cout cerr << "OUT: "
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)

template<typename T> void read(T& x) { cin >> x;}
template<typename T1, typename T2> void read(pair<T1, T2>& p) { read(p.first), read(p.second);}
template<typename T> void read(vector<T>& v) { for (auto& x : v) read(x); }
template<typename T1, typename T2> void read(T1& x, T2& y) { read(x), read(y); }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z) { read(x), read(y), read(z); }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz) { read(x), read(y), read(z), read(zz); }
template<typename T> void print(vector<T>& v) { for (auto& x : v) cout << x << ' '; cout << endl; }

#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(v) sort(all(v)), v.erase(unique(all(v)), (v).end())
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
#define QYES quit("YES")
#define QNO quit("NO")

#define int long long
#define double long double
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=20;



void solve();

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	// cin >> tt;
	while(tt--) solve();
	return 0;
}




int n, k, m, q;
vector<multiset<pair<int, int>>> adj;
set<pair<int, int>> todo;
vector<bool> vis;

int propagate() {
	vector<vector<int>> edges;
	int cnt=0;
	while (!todo.empty() && todo.begin()->fi==1) {
		int u=todo.begin()->se, v=adj[u].begin()->fi, w=adj[u].begin()->se; todo.erase(todo.begin()), adj[u].erase(adj[u].begin());
		if (adj[v].count({u, -w})) adj[v].extract({u, -w}), todo.erase({sz(adj[v])+1, v}), todo.insert({sz(adj[v]), v});
		vis[u]=1, cnt+=w;
		edges.pb({u, v, w});
	}
	return cnt;
}


void solve() {
	read(n, k);
	adj.clear(), adj.resize(2*n);
	for (int i=0; i<2*n; i++) {
		int u, v, w; read(u, v, w); u--, v+=n-1;
		adj[u].insert({v, w}), adj[v].insert({u, -w});
	}
	n*=2;
	vis.clear(), vis.resize(n, 0);
	for (int i=0; i<n; i++) {
		todo.insert({sz(adj[i]), i});
		if (adj[i].empty()) QNO;
	}
	int val=propagate()+k;
	for (int i=0; i<n; i++) if (sz(adj[i])) {
		assert(sz(adj[i])==2);
	} else if (!vis[i]) QNO;
	vector<int> vec;
	for (int i=0; i<n; i++) if (sz(adj[i]) && !vis[i]) {
		adj[i].erase(adj[i].begin());
		todo.erase({sz(adj[i])+1, i}), todo.insert({sz(adj[i]), i});
		vec.pb(abs(propagate()));
		val-=vec.back(); vec.back()*=2;
	}
	if (val>=0) QYES;
	val*=-1;
	dbg(val);
	sort(all(vec));
	bitset<300000> dp; dp[0]=1;
	for (int i=0; i<sz(vec); i++) {
		dp|=dp<<vec[i];
	}
	for (int i=0; i<=2*k; i++) if (dp[i+val]) QYES;
	QNO;
}

• Subtask 1: 18 / 18
• Subtask 2: 30 / 30
• Subtask 3: 23 / 23
• Subtask 4: 29 / 29