Submission #965734

#	Time	Username	Problem	Language	Result	Execution time	Memory
965734		willychan	Swapping Cities (APIO20_swap)	C++17	17 / 100	2095 ms	10520 KiB

swap

#include "swap.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
struct edge{
	int a;
	int b;
	int w;
};
vector<edge> es;
int n;
int m;
vector<vector<int> > side;
vector<bool> vis;
void init(int N, int M,std::vector<int> U, std::vector<int> V, std::vector<int> W) {
	n = N;
	m = M;
	vis.resize(n,0);
	side.resize(n);
	for(int i=0;i<M;i++){
		es.push_back({U[i],V[i],W[i]});
	}
	sort(es.begin(),es.end(),[](const edge &x,const edge &y){return x.w<y.w;});
}
bool dfs(int cur,int p){
	vis[cur]=1;
	bool k=0;
	for(auto i : side[cur])	{
		int v = es[i].a+es[i].b-cur;
		if(vis[v] && v!=p) k=1;
		if(!vis[v]) if(dfs(v,cur)) k=1;
	}
	return k;
}



int check(int x,int y){
	fill(vis.begin(),vis.end(),0);
	bool cir = dfs(x,-1);
	if(!vis[y]) return 0;
	if(cir) return 1;
	int maxn = 0;
	for(int i=0;i<n;i++) if(vis[i]) maxn=max((int)side[i].size(),maxn);
	return maxn>2;
}

int getMinimumFuelCapacity(int X, int Y) {
  for(int i=0;i<n;i++) side[i].clear();
  for(int i=0;i<m;i++){
  	side[es[i].a].push_back(i);
  	side[es[i].b].push_back(i);
	if(check(X,Y)) return es[i].w;
  }
  return -1;
}

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