Submission #147844

#	Time	Username	Problem	Language	Result	Execution time	Memory
147844		cheetose	Beads and wires (APIO14_beads)	C++11	0 / 100	7 ms	4984 KiB

beads

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<vector>
#include<queue>
#include<bitset>
#include<string>
#include<stack>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<complex>
#include<cmath>
#include<iomanip>
#include<numeric>
#include<algorithm>
#include<list>
#include<functional>
#include<cassert>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 987654321987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a));
#define MEM_1(a) memset((a),-1,sizeof(a));
#define ALL(a) a.begin(),a.end()
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<ld, ld> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<double> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int,int,int,int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const ll MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) {ll ret=1; for(;b;b>>=1,a=(a*a)%MMM)if(b&1)ret=(ret*a)% MMM; return ret; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { if (a == 0 || b == 0)return a + b; return a*(b / gcd(a, b)); }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };

int n;
VPi v[200001];
Pi d[200001][2];
void dfs(int N,int p,int c)
{
	Vi vv;
	for(auto P:v[N])
	{
		if(P.X==p)continue;
		vv.pb(P.X);
		dfs(P.X,N,P.Y);
	}
	sort(ALL(vv),[&](int a,int b){
		return d[a][0].X+d[a][0].Y-d[a][1].X>d[b][0].X+d[b][0].Y-d[b][1].X;
	});
	int t=0;
	if(vv.size()>=2)
	{
		t=d[vv[0]][0].X+d[vv[0]][0].Y+d[vv[1]][0].X+d[vv[1]][0].Y-d[vv[0]][1].X-d[vv[1]][1].X;
		if(t>=0)
		{
			int tmp=0;
			tmp+=t+d[vv[0]][1].X+d[vv[1]][1].X;
			fup(i,2,(int)vv.size()-1,1)tmp+=d[vv[i]][1].X;
			d[N][0].X=tmp;
		}
	}
	if(t<0 || vv.size()<2)
	{
		int tmp=0;
		fup(i,0,(int)vv.size()-1,1)tmp+=d[vv[i]][1].X;
		d[N][0].X=tmp;
	}
	sort(ALL(vv),[&](int a,int b){
		return d[a][0].Y>d[b][0].Y;
	});
	if(vv.size())d[N][1].X+=d[vv[0]][0].Y+c;
	fup(i,0,(int)vv.size()-1,1)d[N][1].X+=d[vv[i]][1].X;
	d[N][0].Y=c;
}
int main() {
	scanf("%d",&n);
	fup(i,1,n-1,1)
	{
		int x,y,z;
		scanf("%d%d%d",&x,&y,&z);
		v[x].pb(mp(y,z));
		v[y].pb(mp(x,z));
	}
	dfs(1,-1,0);
	printf("%d",d[1][0].X);
}

Compilation message (stderr)

beads.cpp: In function 'int main()':
beads.cpp:104:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
beads.cpp:108:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&x,&y,&z);
   ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43