Submission #482997

#	Time	Username	Problem	Language	Result	Execution time	Memory
482997		PoPularPlusPlus	Swapping Cities (APIO20_swap)	C++17	17 / 100	106 ms	41012 KiB

swap

#include "swap.h"

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long 
#define pb(e) push_back(e)
#define sv(a) sort(a.begin(),a.end())
#define sa(a,n) sort(a,a+n)
#define mp(a,b) make_pair(a,b)
#define vf first
#define vs second
#define ar array
#define all(x) x.begin(),x.end()
const int inf = 0x3f3f3f3f;
const int mod = 1000000007; 
const double PI=3.14159265358979323846264338327950288419716939937510582097494459230;
bool remender(ll a , ll b){return a%b;}

const int N = 100002 , M = 200003 , l = 25;
vector<int> adj[M + N];
int degree[N];
int root , ans[N];
int timer;
int tin[N], tout[N];
int up[N][l + 5];

void dfs(int v, int p){
    tin[v] = ++timer;
    up[v][0] = p;
    for (int i = 1; i <= l; ++i)
        up[v][i] = up[up[v][i-1]][i-1];

    for (int u : adj[v]) {
        if (u != p){
			if(ans[u] == -1 && ans[v] != -1)ans[u] = ans[v];
            dfs(u, v);
		}
    }

    tout[v] = ++timer;
}

bool is_ancestor(int u, int v){
    return tin[u] <= tin[v] && tout[u] >= tout[v];
}

int lca(int u, int v){
    if (is_ancestor(u, v))
        return u;
    if (is_ancestor(v, u))
        return v;
    for (int i = l; i >= 0; --i) {
        if (!is_ancestor(up[u][i], v))
            u = up[u][i];
    }
    return up[u][0];
}

struct UFDS {

vector<int> p,siz;

void init(int n){
	p.resize(n + 2);
	siz.resize(n + 2);
	for(int i = 0; i <= n; i++){
		p[i] = i;
		siz[i] = 1;
	}
}

int get(int x){
	return p[x]=(x==p[x] ? x : get(p[x]));
}

void unio(int u , int v , int w , int a , int b){
	// cycle 
	if(a == b){
		if(ans[a] == -1){
			adj[root].pb(a);
			p[a] = root;
			degree[u]++;
			degree[v]++;
			ans[root] = w;
		}
		else return;
	}
	else {
		adj[root].pb(a);
		adj[root].pb(b);
		p[a] = root;
		p[b] = root;
		degree[u]++;
		degree[v]++;
		if(ans[a] != -1 || ans[b] != -1 || degree[u] == 3 || degree[v] == 3)ans[root] = w;
	}
	root++;
}
};

UFDS d;

void init(int n , int m , vector<int> a , vector<int> b , vector<int> c){
	memset(degree,0,sizeof degree);
	memset(ans,-1,sizeof ans);
	d.init(n + m + 2);
	timer = 0;
	root = n;
	vector<pair<int , pair<int,int>>> lol;
	for(int i = 0; i < m; i++){
		lol.pb(mp(c[i] , mp(a[i] , b[i])));
		//lol[b[i]].pb(mp(a[i] , c[i]));
	}
	sv(lol);
	for(int i = 0; i < m; i++){
		d.unio(lol[i].vs.vf , lol[i].vs.vs , lol[i].vf , d.get(lol[i].vs.vf) , d.get(lol[i].vs.vs));
	}
	dfs(root-1,root-1);
}

int getMinimumFuelCapacity(int x, int y){
	int lc = lca(x , y);
	return ans[lc];
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 17 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27