Submission #419668

#	Time	Username	Problem	Language	Result	Execution time	Memory
419668		amunduzbaev	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	592 ms	54616 KiB

election_campaign

/* made by amunduzbaev */
 
//~ #include <ext/pb_ds/assoc_container.hpp>
//~ #include <ext/pb_ds/tree_policy.hpp>
#include "bits/stdc++.h"
 
using namespace std;
//~ using namespace __gnu_pbds;

#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(),x.rend()
#define NeedForSpeed ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define vv vector
#define mem(arr, v) memset(arr, v, sizeof arr)
#define int long long
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii; 
typedef vector<int> vii;
typedef vector<pii> vpii;
template<class T> bool umin(T& a, const T& b) { return a > b ? a = b, true : false; }
template<class T> bool umax(T& a, const T& b) { return a < b ? a = b, true : false; }
template<int sz> using tut = array<int, sz>;
void usaco(string s) { freopen((s+".in").c_str(),"r",stdin);  
	freopen((s+".out").c_str(),"w",stdout); NeedForSpeed }
//~ template<class T> using oset = tree<T, 
//~ null_type, less_equal<T>, rb_tree_tag, 
//~ tree_order_statistics_node_update>;
 
const int N = 2e5+5;
const int mod = 1e9+7;
const ll inf = 1e18;
const ld Pi = acos(-1);
 
#define MULTI 0
int n, m, k, s, t, q, ans, res[N], a[N];
int tin[N], tout[N], par[N][20], sz[N], d[N], hh[N];
int in = 0, pos[N], fir[N];
vv<tut<3>> qq[N];
vii edges[N];

void dfs(int u, int p = -1){
	tin[u] = t++, sz[u] = 1;
	for(int i=1;i<20;i++) par[u][i] = par[par[u][i-1]][i-1];
	for(auto x : edges[u]){
		if(x == p) continue;
		par[x][0] = u, d[x] = d[u] + 1, dfs(x, u);
		sz[u] += sz[x];
		if(sz[x] > sz[hh[u]]) hh[u] = x;
	} tout[u] = t-1;
}

void dec(int u, int h){
	fir[u] = h, pos[u] = in++;
	if(hh[u]) dec(hh[u], h);
	for(auto x : edges[u]){
		if(x == par[u][0]) continue;
		if(x != hh[u]) dec(x, x);
	}
}

bool anc(int a, int b){ return (tin[a] <= tin[b] && tout[b] <= tout[a]); }
int LCA(int a, int b){
	if(anc(a, b)) return a;
	if(anc(b, a)) return b;
	for(int i=19;i>=0;i--){
		if(!anc(par[a][i], b)) a = par[a][i];
	} return par[a][0];
} 

struct tree{
	int tree[4*N];
	void sett(int i, int v, int lx = 0, int rx = n, int x = 1){
		if(lx == rx) { tree[x] = v; return; }
		int m = (lx + rx)>>1;
		if(i <= m) sett(i, v, lx, m, x<<1);
		else sett(i, v, m+1, rx, x<<1|1);
		tree[x] = tree[x<<1] + tree[x<<1|1];
	}
	
	int find(int l, int r, int lx = 0, int rx = n, int x = 1){
		if(lx > r || rx < l) return 0;
		if(lx >= l && rx <= r) return tree[x];
		int m = (lx + rx)>>1;
		return find(l, r, lx, m, x<<1) + find(l, r, m+1, rx, x<<1|1);
	}
}tt1, tt2;

int find(tree& tt, int a, int b){
	int res = 0;
	for(; fir[a] != fir[b]; b = par[fir[b]][0]){
		if(d[fir[a]] > d[fir[b]]) swap(a, b);
		res += tt.find(pos[fir[b]], pos[b]);
	} res += tt.find(min(pos[a], pos[b]), max(pos[a], pos[b]));
	return res;
}

void dfs2(int u, int p = -1){
	for(auto x : edges[u]) if(x != p) dfs2(x, u), res[u] += res[x];
	tt1.sett(pos[u], res[u]); 
	for(auto x : qq[u]){
		int sum = find(tt1, x[0], x[1]) - find(tt2, x[0], x[1]);
		//~ cout<<x[0]<<" "<<x[1]<<" "<<find(tt1, x[0], x[1])<<" "<<find(tt2, x[0], x[1])<<"\n";
		
		umax(res[u], sum + x[2]);
	} tt2.sett(pos[u], res[u]);
	//~ cout<<u<<" "<<res[u]<<"\n";
}

void solve(int t_case){
	cin>>n;
	tin[0] = 0, tout[0] = mod;
	for(int i=1;i<n;i++){
		int a, b; cin>>a>>b;
		edges[a].pb(b), edges[b].pb(a);
	}
	
	dfs(1);
	cin>>m;
	for(int i=0;i<m;i++){
		int a, b, c; cin>>a>>b>>c;
		int lca = LCA(a, b);
		qq[lca].pb({a, b, c});
	}
	
	//~ cout<<"\n";
	dec(1, 1);
	dfs2(1);
	cout<<res[1]<<"\n";
}

signed main(){
	NeedForSpeed
	if(MULTI){
		int t; cin>>t;
		for(int t_case = 1; t_case <= t; t_case++) solve(t_case);
	} else solve(1);
	return 0;
}

Compilation message (stderr)

election_campaign.cpp: In function 'void usaco(std::string)':
election_campaign.cpp:32:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 | void usaco(string s) { freopen((s+".in").c_str(),"r",stdin);
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:33:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |  freopen((s+".out").c_str(),"w",stdout); NeedForSpeed }
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40