#include "parks.h"
#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
template<typename t>
using matrix = vector<vector<t>>;
int construct_roads(std::vector<int> x, std::vector<int> y) {
if (x.size() == 1) {
build({}, {}, {}, {});
return 1;
}
int n = x.size();
std::vector<int> u, v, a(n-1), b(n-1);
int dx[]{1,0,-1,0};
int dy[]{0,1,0,-1};
vector<int> pai(n);
int comp = n;
iota(all(pai),0);
auto find =[&](int id, auto f){
if(pai[id] == id)
return id;
return pai[id] = f(pai[id],f);
};
auto onion =[&](int a, int b){
int pa = find(a,find);
int pb = find(b,find);
if(pa != pb){
comp--;
u.push_back(a);
v.push_back(b);
}
pai[pa] = pb;
};
map<pii,int> fount;
map<pii,int> road;
for(int i = 0; i < n; i++)
fount[{x[i],y[i]}] = i;
for(int i = 0; i < n; i++){
for(int j = 0; j < 4; j++){
int xi = x[i] + dx[j]*2, yi = y[i]+dy[j]*2;
if(fount.count({xi,yi}))
onion(i,fount[{xi,yi}]);
}
}
if(comp > 1)
return 0;
for(int i = 0; i < n; i++){
int cx = (x[u[i]]+x[v[i]])>>1, cy = (y[u[i]]+y[v[i]])>>1;
road[{cx,cy}] = i;
}
auto adj =[&](int x, int y){
vector<int> ret;
for(int i = 0; i < 4; i++){
int xi = x + dx[i], yi = y + dy[i];
if(roads.count({xi,yi}))
ret.push_back(roads[{xi,yi}]);
}
return ret;
};
vector<int> st;
vector<int> check(n-1);
for(int i = 0; i < n-1; i++){
int cx = (x[u[i]]+x[v[i]])>>1, cy = (y[u[i]]+y[v[i]])>>1;
if(adj(cx,cy).size() == 1)
st.push_back(i);
}
set<pii> bench;
while(!st.empty()){
int cur = st.back();
st.pop_back();
if(check[cur])
continue;
check[cur] = 1;
int cx = (x[u[cur]]+x[v[cur]])>>1, cy = (y[u[cur]]+y[v[cur]])>>1;
bool ok = 0;
for(int j = 0; j < 4; j++){
int xi = cx + dx[j], yi = cy+dy[j];
if(!((xi&1)&&(yi&1)))
continue;
if(!bench.count({xi,yi})){
a[cur] = xi;
b[cur] =yi;
bench.insert({xi,yi});
ok = 1;
break;
}
}
if(!ok)
return 0;
road.erase({cx,cy});
vector<int> call = adj(a[cur],b[cur]);
for(int i : call)
if(!check[i])
st.push_back(i);
}
for(int i : o){
if(check[i])
continue;
int cx = (x[u[i]]+x[v[i]])>>1, cy = (y[u[i]]+y[v[i]])>>1;
bool ok = 0;
for(int j = 0; j < 4; j++){
int xi = cx + dx[j], yi = cy+dy[j];
if(!((xi&1)&&(yi&1)))
continue;
if(!bench.count({xi,yi})){
a[i] = xi;
b[i] =yi;
bench.insert({xi,yi});
ok = 1;
break;
}
}
if(!ok)
return 0;
}
build(u,v,a,b);
return 1;
}
Compilation message
parks.cpp: In lambda function:
parks.cpp:72:16: error: 'roads' was not declared in this scope; did you mean 'road'?
72 | if(roads.count({xi,yi}))
| ^~~~~
| road
parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:118:17: error: 'o' was not declared in this scope
118 | for(int i : o){
| ^
