Submission #490750

#	Time	Username	Problem	Language	Result	Execution time	Memory
490750		NhatMinh0208	Tug of War (BOI15_tug)	C++14	100 / 100	747 ms	10988 KiB

tug

#ifndef CPL_TEMPLATE
#define CPL_TEMPLATE
/*
	Normie's Template v2.5
	Changes:
    Added warning against using pragmas on USACO.
*/
// Standard library in one include.
#include <bits/stdc++.h>
using namespace std;
 
// ordered_set library.
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set(el) tree<el,null_type,less<el>,rb_tree_tag,tree_order_statistics_node_update>
 
// AtCoder library. (Comment out these two lines if you're not submitting in AtCoder.) (Or if you want to use it in other judges, run expander.py first.)
//#include <atcoder/all>
//using namespace atcoder;

//Pragmas (Comment out these three lines if you're submitting in szkopul or USACO.)
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast,unroll-loops,tree-vectorize")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
 
//File I/O.
#define FILE_IN "cseq.inp"
#define FILE_OUT "cseq.out"
#define ofile freopen(FILE_IN,"r",stdin);freopen(FILE_OUT,"w",stdout)
 
//Fast I/O.
#define fio ios::sync_with_stdio(0);cin.tie(0)
#define nfio cin.tie(0)
#define endl "\n"
 
//Order checking.
#define ord(a,b,c) ((a>=b)and(b>=c))
 
//min/max redefines, so i dont have to resolve annoying compile errors.
#define min(a,b) (((a)<(b))?(a):(b))
#define max(a,b) (((a)>(b))?(a):(b))

// Fast min/max assigns to use with AVX.
// Requires g++ 9.2.0.
template<typename T>
__attribute__((always_inline)) void chkmin(T& a, const T& b) {
    a=(a<b)?a:b;
}

template<typename T>
__attribute__((always_inline)) void chkmax(T& a, const T& b) {
    a=(a>b)?a:b;
}
 
//Constants.
#define MOD (ll(998244353))
#define MAX 300001
#define mag 320
const long double PI=3.14159265358979;
 
//Pairs and 3-pairs.
#define p1 first
#define p2 second.first
#define p3 second.second
#define fi first
#define se second
#define pii(element_type) pair<element_type,element_type>
#define piii(element_type) pair<element_type,pii(element_type)>
 
//Quick power of 2.
#define pow2(x) (ll(1)<<x)
 
//Short for-loops.
#define ff(i,__,___) for(int i=__;i<=___;i++)
#define rr(i,__,___) for(int i=__;i>=___;i--)
 
//Typedefs.
#define bi BigInt
typedef long long ll;
typedef long double ld;
typedef short sh;

// Binpow and stuff
ll BOW(ll a, ll x, ll p)
{
	if (!x) return 1;
	ll res=BOW(a,x/2,p);
	res*=res;
	res%=p;
	if (x%2) res*=a;
	return res%p;
}
ll INV(ll a, ll p)
{
	return BOW(a,p-2,p);
}
//---------END-------//
#endif
vector<int> sus;
int n,m,i,j,k,t,t1,u,v,a,b;
int l[60001],r[60001],s[60001];
int mk[60001];
bitset<600001> bs;
set<int> gt[60001];
void dfs(int x, int p, int c) {
	mk[x]=1;
	if (c==0) {
		u+=s[p];
	}
	else {
		v+=s[p];
	}
		for (auto g : gt[x]) if (g-p) {
			if (!mk[l[g]]) {
				dfs(l[g],g,c^1);
			}
			if (!mk[r[g]]) {
				dfs(r[g],g,c^1);
			}
		}
}
int main()
{
	fio;
	cin>>n>>m;
	for (i=1;i<=2*n;i++) {
		cin>>l[i]>>r[i]>>s[i];
		r[i]+=n;
		t+=s[i];
		gt[l[i]].insert(i);	gt[r[i]].insert(i);
	}
	sus.clear();
	bs[0]=1;
	for (i=1;i<=2*n;i++) if (gt[i].size()==1) {
		sus.push_back(i);
	}
	for (i=0;i<sus.size();i++) {
		u=sus[i];
		mk[u]=1;
		v=(*(gt[u].begin()));
		gt[l[v]].erase(v);
		gt[r[v]].erase(v);
		if (l[v]==u) {
			bs<<=s[v];
			if (gt[r[v]].size()==1) {
				sus.push_back(r[v]);
			}
		}
		else {
			if (gt[l[v]].size()==1) {
				sus.push_back(l[v]);
			}
		}
	}
	for (i=1;i<=2*n;i++) {
		if (gt[i].size()==2 || (gt[i].size()==0 && mk[i])); else {
			return cout<<"NO",0;
		}
	}
  	//cout<<"CLEARED\n";
	for (i=1;i<=2*n;i++) {
		if (!mk[i]) {
			u=0;
			v=0;
			a=(*(gt[i].begin()));
			dfs(i,a,0);
      //    cout<<u<<' '<<v<<endl;
			if (u>v) swap(u,v);
			bs<<=u;
			bs|=(bs<<(v-u));
		}
	}
	for (i=0;i<=t;i++) {
		if (bs[i] && abs(i-(t-i))<=m) {
			return cout<<"YES",0;
		}
	}
	cout<<"NO";
}

Compilation message (stderr)

tug.cpp:23: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
   23 | #pragma comment(linker, "/stack:200000000")
      | 
tug.cpp: In function 'int main()':
tug.cpp:138:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |  for (i=0;i<sus.size();i++) {
      |           ~^~~~~~~~~~~

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