#include "parks.h"
#include<bits/stdc++.h>
using namespace std;
vector<int>parent(2e5);
vector<int>siz(2e5);
int maxxy=0;
void makesets(int v){
parent[v]=v;
siz[v]=1;
}
int findsets (int v){
if (v==parent[v])return v;
parent[v]=findsets(parent[v]);
return parent[v];
}
void unionset(int a,int b){
a = findsets(a);
b =findsets(b);
if (a==b)return;
if (siz[a]<siz[b])swap(a,b);
siz[a]+=siz[b];
maxxy=max(siz[a],maxxy);
parent[b]=a;
}
struct point {
int x,y,index;
};
bool dist(point x,point y){
if (pow(x.x - y.x,2)+pow(x.y-y.y,2)!=4)return false;
return true;
}
int binarysearch(int seg,int eq,int n,vector<point>arr){
int left = 0;
int right = n-1;
while(left<=right){
int mid = (left + right) >> 1;
if (arr[mid].x<seg)left= mid + 1;
else if (arr[mid].x>seg)right = mid-1;
else {
if (arr[mid].y<eq){
left=mid+1;
}
else if (arr[mid].y>eq){
right = mid-1;
}
else return mid;
}
}
return -1;
}
//void build(vector<int> u, vector<int> v, vector<int> a, vector<int> b) ;
int construct_roads(std::vector<int> x, std::vector<int> y) {
vector<point>arr;
int n = x.size();
bool ok=true;
for (int i = 0 ;i<n;++i){
if (x[i]!=x[0])ok=false;
arr.push_back({x[i],y[i],i});
makesets(i);
}
vector<int>ansx,ansy,ansxi,ansyi;
if (ok){
sort(arr.begin(),arr.end(),[&](point a,point b){
return a.y<b.y;
});
for (int i = 1;i<n;++i){
if (dist(arr[i],arr[i-1])){
ansx.push_back(min(arr[i].x,arr[i-1].x) + 1);
ansy.push_back(min(arr[i].y,arr[i-1].y)+1);
ansxi.push_back(arr[i].index);
ansyi.push_back(arr[i-1].index);
}
else return 0;
}
build(ansxi,ansyi,ansx,ansy);
return 1;}
else{
vector<vector<bool>>p(3,vector<bool>(1e5 + 5,false));
sort(arr.begin(),arr.end(),[&](point a,point b){
if (a.x==b.x)return a.y<b.y;
return a.x<b.x;
});
vector<int>check;
int i =1;
for (;i<n;++i){
if (arr[i].x!=2)break;
if (dist(arr[i],arr[i-1])){
ansx.push_back(min(arr[i].x,arr[i-1].x) - 1);
ansy.push_back(min(arr[i].y,arr[i-1].y) + 1);
ansxi.push_back(arr[i].index);
ansyi.push_back(arr[i-1].index);
unionset(i-1,i);
p[ansx.back()/2][ansy.back()/2]=true;
}
else {
check.push_back(i);
check.push_back(i-1);
}
}
check.push_back(i);
check.push_back(i-1);
for (;i<n;++i){
if (arr[i-1].x==2)continue;
if (dist(arr[i],arr[i-1])){
ansx.push_back(min(arr[i].x,arr[i-1].x) + 1);
ansy.push_back(min(arr[i].y,arr[i-1].y) + 1);
ansxi.push_back(arr[i].index);
ansyi.push_back(arr[i-1].index);
unionset(i-1,i);
p[ansx.back()/2][ansy.back()/2]=true;
}
else {
check.push_back(i-1);
}
}
for (int l = 0;l<check.size();++l){
int k = check[l];
if (maxxy==n)break;
int ls=(arr[k].x==2)?binarysearch(arr[k].x+2,arr[k].y,n,arr):-1;
int lt =(arr[k].x==4)?binarysearch(arr[k].x-2,arr[k].y,n,arr):-1;
vector<int>crr;
if (ls!=-1)crr.push_back(ls);
if (lt!=-1)crr.push_back(lt);
for (auto j:crr){
if (dist(arr[j],arr[k])&&findsets(j)!=findsets(k)){
int first1=min(arr[k].x,arr[j].x) + 1;
int second1=min(arr[k].y,arr[j].y) + 1;
int second2 = min(arr[k].y,arr[j].y) - 1;
if (!p[first1/2][second1/2]){
ok=true;
ansx.push_back(first1);
ansy.push_back(second1);
ansxi.push_back(arr[j].index);
ansyi.push_back(arr[k].index);
unionset(j,k);
p[ansx.back()/2][ansy.back()/2]=true;
break;
}
if (!p[first1/2][second1/2]){
ok=true;
ansx.push_back(first1);
ansy.push_back(second2);
ansxi.push_back(arr[j].index);
ansyi.push_back(arr[k].index);
unionset(j,k);
p[ansx.back()/2][ansy.back()/2]=true;
break;
}
}
}
}
if (maxxy!=n)return 0;
build(ansxi,ansyi,ansx,ansy);
return 1;
}
Compilation message
parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:119:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
119 | for (int l = 0;l<check.size();++l){
| ~^~~~~~~~~~~~~
parks.cpp:160:5: error: expected '}' at end of input
160 | }
| ^
parks.cpp:52:61: note: to match this '{'
52 | int construct_roads(std::vector<int> x, std::vector<int> y) {
| ^
