Submission #740800

#	Time	Username	Problem	Language	Result	Execution time	Memory
740800		penguin133	Swapping Cities (APIO20_swap)	C++17	0 / 100	101 ms	10216 KiB

swap

#include <bits/stdc++.h>
using namespace std;

//#include "swap.h"
//#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

vector <pi> adj[100005];
int par[100005];
pi mn[100005];
pi mn2[100005];
int mn3[100005];
int getr(int x){return (par[x] == x ? x : par[x] =getr(par[x]));}
void merge(int a, int b){a = getr(a); b = getr(b); if(a != b)par[b] = a;}

void init(int N, int M,
     std::vector<int> U, std::vector<int> V, std::vector<int> W) {
	vector <pii> bru;
	for(int i=0;i<M;i++)bru.push_back({W[i], {U[i], V[i]}});
	for(int i=0;i<N;i++)mn[i] = mn2[i] = {2e9, 0}, mn3[i] = 2e9;
	sort(bru.begin(), bru.end());
	for(auto i : bru){
		int a = i.se.fi, b = i.se.se, w = i.fi;
		if(mn[a].fi == 2e9)mn[a] = {w, b};
		else if(mn2[a].fi == 2e9)mn2[a] = {w, b};
		else if(mn3[a] == 2e9)mn3[a] = w;
		if(mn[b].fi == 2e9)mn[b] = {w, a};
		else if(mn2[b].fi == 2e9)mn2[b] = {w, a};
		else if(mn3[b] == 2e9)mn3[b] = w;
		if(getr(a) == getr(b))continue;
		adj[a].push_back({b, w});
		adj[b].push_back({a, w});
		merge(a, b);
	}
}

vector <int> path;
int tmp;
int tgt;
bool tr(int x, int par){
	if(x == tgt){
		path.push_back(x);
		return 1;
	}
	bool res = 0;
	for(auto [i, j] : adj[x]){
		if(i == par)continue;
		bool tt = tr(i, x);
		res |= tt;
		if(tt)tmp = max(tmp, j);
	}
	if(res)path.push_back(x);
	return res;
}

int getMinimumFuelCapacity(int X, int Y) {
  tgt = Y;
  path.clear();
  tmp = 0;
  int bruh = tr(X, -1);
  int ouch = 2e9;
  for(int i=0;i<(int)path.size();i++){
	  int halp = mn[path[i]].se;
	  if(!(i && halp == path[i-1]) || (i < (int)path.size() - 1 && path[i+1] == halp))ouch = min(ouch, mn[path[i]].fi);
	  halp = mn2[path[i]].se;
	  if(!(i && halp == path[i-1]) || (i < (int)path.size() - 1 && path[i+1] == halp))ouch = min(ouch, mn2[path[i]].fi);
	  ouch = min(ouch, mn3[path[i]]);
  }
  if(ouch == 2e9)return -1;
  return max(ouch, tmp);
}

Compilation message (stderr)

swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:67:7: warning: unused variable 'bruh' [-Wunused-variable]
   67 |   int bruh = tr(X, -1);
      |       ^~~~

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