#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define repa(i,a,b) for(int i = (a); i >= (b); i--)
#define pll pair<lli,lli>
#define MAX 200000
//para los pares en general
#define xx first
#define yy second
lli n,a,b,uf[MAX+2],uniones;
lli s[2] = {-1,1};
map<pll,lli> mapa,a_vis,b_vis;
lli dir[8] = {0,-2,0,2,2,0,-2,0};
vector<pll> aristas;
vector<int> u,v,b_x,b_y;
lli sube(lli pos) {
if (uf[pos] == pos) return pos;
uf[pos] = sube(uf[pos]);
return uf[pos];
}
int construct_roads(std::vector<int> x, std::vector<int> y) {
n = x.size();
rep(i,0,n-1) {
uf[i] = i+1;
mapa[{x[i],y[i]}] = i;
rep(j,0,3) {
a = x[i] + dir[j];
b = y[i] + dir[j+4];
if(mapa.find({a,b}) != mapa.end()) {
aristas.push_back({i,mapa[{a,b}]});
a = sube(mapa[{a,b}]);
b = sube(i);
if (a != b) {
uniones++;
uf[a] = b;
}
}
}
}
2
if(uniones != n-1) return 0;
for (auto act : aristas) {
//debugsl(act.first);
//debug(act.second);
while (a_vis.find(act) == a_vis.end()) {
a_vis[act] = 1;
swap(act.first,act.second);
a_vis[act] = 1;
//opciones para colocar la banca
pll w = {(x[act.first] + x[act.second])/2, (y[act.first] + y[act.second])/2};
pll z = {(x[act.first] + x[act.second])/2, (y[act.first] + y[act.second])/2};
if (x[act.first] == x[act.second]) {
w.xx++;
z.xx--;
}
else {
w.yy++;
z.yy--;
}
if (b_vis.find(w) == mapa.end()) { //pongo mi banca en w
b_vis[w] = 1;
b_x.push_back(w.xx);
b_y.push_back(w.yy);
u.push_back(act.first);
v.push_back(act.second);
}
else {
b_vis[z] = 1;
b_x.push_back(z.xx);
b_y.push_back(z.yy);
u.push_back(act.first);
v.push_back(act.second);
w = z;
}
//busco si es que el esta en una tripleta y continuo la busqueda
rep(i,0,1) {
rep(j,0,1) {
z.xx = w.xx + s[i];
z.yy = w.yy + s[j];
if (z.xx == x[act.first] && z.yy == y[act.first]) continue;
if (z.xx == x[act.second] && z.yy == y[act.second]) continue;
if (mapa.find(z) == mapa.end()) continue;
if (z.xx == x[act.first] || z.yy == y[act.first]) act.second = mapa[z];
else act.first = mapa[z];
}
}
}
}
build(u,v,b_x,b_y);
return 1;
}
Compilation message
parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:52:2: error: expected ';' before 'if'
52 | 2
| ^
| ;
53 | if(uniones != n-1) return 0;
| ~~
parks.cpp:52:1: warning: statement has no effect [-Wunused-value]
52 | 2
| ^
