Submission #199605

#	Time	Username	Problem	Language	Result	Execution time	Memory
199605		cheetose	Harbingers (CEOI09_harbingers)	C++11	0 / 100	229 ms	26360 KiB

harbingers

#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 int 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 };

struct line {  // y = a*x + b
	ll a, b;
};

struct convexhull_trick {
	int e = 0;
	vector<line> st;
	double cross(int a, int b) {
		return 1.0 * (st[a].b - st[b].b) / (st[b].a - st[a].a);
	}
	void insert(line v) {
		while (st.size()>2 && cross(e - 2, e - 1) > cross(e - 1, e))
		{
			e--;
			st.pop_back();
		}
		st.pb(v);
		e++;
	}
	ll query(ll x) {
		if (st.empty())return 0;
		int l = 0, r = e - 1;
		while (l != r) {
			int m = (l + r) / 2;
			if (cross(m, m + 1) <= x) l = m + 1;
			else r = m;
		}
		return st[l].a*x + st[l].b;
	}
}cht[100001];

VPll v[100001];
ll s[100001], t[100001], ans[100001];
int cnt[100001],hld[100001],parent[100001];
void dfs1(int N, int p=-1)
{
	parent[N] = p;
	cnt[N] = 1;
	for (Pll P : v[N])
	{
		if (P.X == p)continue;
		dfs1(P.X, N);
		cnt[N] += cnt[P.X];
	}
}

void HLD(int N, int p=-1)
{
	int c = -1;
	for (auto next : v[N])
	{
		if (next.X == p)continue;
		if (c == -1 || cnt[next.X]>cnt[c])c = next.X;
	}
	if (c != -1)
	{
		hld[c] = hld[N];
		HLD(c, N);
	}
	for (auto next : v[N])
	{
		if (next.X == p || next.X == c)continue;
		hld[next.X] = next.X;
		HLD(next.X, N);
	}
}
void dfs(int N, ll D, int p = -1)
{
	ans[N] = t[N]*D+s[N];
	for (int now = N; now != -1; now = parent[hld[now]])ans[N] = min(ans[N], cht[hld[now]].query(t[N]) + D*t[N] + s[N]);
	cht[hld[N]].insert({ -D,ans[N] });
	for (auto next : v[N])
	{
		if (next.X == p || hld[next.X] == hld[N])continue;
		dfs(next.X, D + next.Y, N);
	}
	for (auto next : v[N])
	{
		if (next.X == p || hld[next.X] == next.X)continue;
		dfs(next.X, D+next.Y, N);
	}
}
int main() {
	int n;
	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));
	}
	fup(i, 2, n, 1)scanf("%lld%lld", s + i, t + i);
	dfs1(1); hld[1] = 1; HLD(1); cht[1].insert({ 0,0 }); dfs(1, 0);
	fup(i, 2, n, 1)printf("%lld ", ans[i]);
}

Compilation message (stderr)

harbingers.cpp: In function 'int main()':
harbingers.cpp:147:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
harbingers.cpp:151:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &x, &y, &z);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:155:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  fup(i, 2, n, 1)scanf("%lld%lld", s + i, t + i);
                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100