#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
#define lli long long
#define rep(i, a, b) for(lli i = (a); i <= (b); ++i)
#define repa(i, a, b) for(lli i = (a); i >= (b); --i)
#define nl "\n"
#define debugsl(x) cout << #x << " = " << x << ", "
#define debug(x) debugsl(x) << nl
#define debugarr(x, a, b) cout << #x << " = ["; rep(ii, a, b) cout << x[ii] << ", "; cout << "]" << nl
#define MAX_N 200002
int dx[4] = {2, 0, -2, 0};
int dy[4] = {0, 2, 0, -2};
map<pair<int, int>, int> fuentes;
vector<int> hijos[MAX_N];
int grupo[MAX_N];
map<pair<int, int>, int> bancas;
std::vector<int> u, v, a, b;
int comp(int a){
if (grupo[a] == a) return a;
else return grupo[a] = comp(grupo[a]);
}
bool une(int a, int b){
int ga = comp(a);
int gb = comp(b);
if (ga == gb) return false;
grupo[ga] = gb;
return true;
}
void dfs(int nodo, int padre, vector<int> &x, vector<int> &y){
for(auto h : hijos[nodo]){
if (h == padre) continue;
if (une(nodo, h)){
// ESTOS DOS NO ESTABAN UNIDOS, ES UN NUEVO CAMINO.
u.push_back(nodo);
v.push_back(h);
int bx, by; // LAS COORDENADAS DE LA BANCA
if (x[nodo] == x[h]){ // ES UNA UNION VERTICAL
by = (y[nodo] > y[h]) ? y[h] + 1 : y[h] - 1;
bx = x[h] + 1;
if (bancas.find({bx, by}) != bancas.end()) bx = x[h] - 1; // SI ESE YA EXISTE, USA LA OTRA OPCION
}
else{ // ES UNA UNION HORIZONTAL
bx = (x[nodo] > x[h]) ? x[h] + 1 : x[h] - 1;
by = y[h] + 1;
if (bancas.find({bx, by}) != bancas.end()) by = y[h] - 1; // SI YA EXISTE, USA LA OTRA OPCION
}
a.push_back(bx);
b.push_back(by);
bancas[{bx, by}] = 1;
dfs(h, nodo, x, y);
}
}
}
int construct_roads(std::vector<int> x, std::vector<int> y) {
if (x.size() == 1) {
build({}, {}, {}, {});
return 1;
}
// ES NECESARIO CONSTRUIR UN GRAFO PARA SABER QUE FUENTES PUEDEN IR UNIDAS CON QUE FUENTES, COMO CADA FUENTE SOLO PUEDE IR UNIDA A 4, ENTONCES USAREMOS UN MAP
int destino;
rep(i, 0, x.size() - 1){
rep(j, 0, 3){
if (fuentes.find({x[i] + dx[j], y[i] + dy[j]}) != fuentes.end()){
destino = fuentes[{x[i] + dx[j], y[i] + dy[j]}];
hijos[i].push_back(destino);
hijos[destino].push_back(i);
}
}
fuentes[{x[i], y[i]}] = i; // AGREGA ESTA FUENTE AL MAPA
}
// AHORA HAZ UNA BUSQUEDA EN PROFUNDIDAD DESDE CUALQUIER FUENTE, AGREGANDO UNICAMENTE CAMINOS SI SON NECESARIOS USANDO UN UNION FIND Y ACOMODANDO LAS BANCAS DE FORMA GREEDY
rep(i, 0, x.size() - 1) grupo[i] = i; // INICIALIZA EL DSU
dfs(0, -1, x, y);
bool ok = true;
rep(i, 0, x.size() - 1) if (comp(i) != 0){
ok = false;
break;
}
if (!ok) return 0;
build(u, v, a, b);
return 1;
}
Compilation message
parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:7:41: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | #define rep(i, a, b) for(lli i = (a); i <= (b); ++i)
| ^
parks.cpp:77:5: note: in expansion of macro 'rep'
77 | rep(i, 0, x.size() - 1){
| ^~~
parks.cpp:7:41: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | #define rep(i, a, b) for(lli i = (a); i <= (b); ++i)
| ^
parks.cpp:89:5: note: in expansion of macro 'rep'
89 | rep(i, 0, x.size() - 1) grupo[i] = i; // INICIALIZA EL DSU
| ^~~
parks.cpp:7:41: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | #define rep(i, a, b) for(lli i = (a); i <= (b); ++i)
| ^
parks.cpp:93:5: note: in expansion of macro 'rep'
93 | rep(i, 0, x.size() - 1) if (comp(i) != 0){
| ^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4940 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
4940 KB |
Solution announced impossible, but it is possible. |
| 3 |
Halted |
0 ms |
0 KB |
- |
