#include "parks.h"
#include "bits/stdc++.h"
using namespace std;
#ifndef EVAL
#include "grader.cpp"
#endif
#define ar array
typedef long long ll;
const int N = 2e5 + 5;
vector<ar<int, 3>> edges[N];
int construct_roads(vector<int> x, vector<int> y) {
int n = x.size();
map<ar<int, 2>, int> ss, mm;
for(int i=0;i<n;i++){
ss[{x[i], y[i]}] = i;
}
vector<ar<int, 2>> e, p;
auto add = [&](int a, int b, int p1, int p2){
edges[a].push_back({b, p1, p2});
edges[b].push_back({a, p1, p2});
};
vector<int> par(n), sz(n, 1);
iota(par.begin(), par.end(), 0);
function<int(int)> f = [&](int x) { return (par[x] == x ? x : par[x] = f(par[x])); };
auto merge = [&](int a, int b){
a = f(a), b = f(b);
if(a == b) return false;
if(sz[a] < sz[b]) swap(a, b);
par[b] = a, sz[a] += sz[b];
return true;
};
for(int i=0;i<n;i++){
if(ss.count({x[i] - 2, y[i]})){
int j = ss[{x[i] - 2, y[i]}];
if(!merge(i, j)) continue;
e.push_back({i, j});
p.push_back({-1, -1});
int u = e.size() - 1;
if(mm.count({x[i] - 1, y[i] - 1})){
int v = mm[{x[i] - 1, y[i] - 1}];
add(u, v, x[i] - 1, y[i] - 1);
mm.erase({x[i] - 1, y[i] - 1});
} else {
mm[{x[i] - 1, y[i] - 1}] = u;
}
if(mm.count({x[i] - 1, y[i] + 1})){
int v = mm[{x[i] - 1, y[i] + 1}];
add(u, v, x[i] - 1, y[i] + 1);
mm.erase({x[i] - 1, y[i] + 1});
} else {
mm[{x[i] - 1, y[i] + 1}] = u;
}
}
if(ss.count({x[i], y[i] - 2})){
int j = ss[{x[i], y[i] - 2}];
if(!merge(i, j)) continue;
e.push_back({i, j});
p.push_back({-1, -1});
int u = e.size() - 1;
if(mm.count({x[i] - 1, y[i] - 1})){
int v = mm[{x[i] - 1, y[i] - 1}];
add(u, v, x[i] - 1, y[i] - 1);
mm.erase({x[i] - 1, y[i] - 1});
} else {
mm[{x[i] - 1, y[i] - 1}] = u;
}
if(mm.count({x[i] + 1, y[i] - 1})){
int v = mm[{x[i] + 1, y[i] - 1}];
add(u, v, x[i] + 1, y[i] - 1);
mm.erase({x[i] + 1, y[i] - 1});
} else {
mm[{x[i] + 1, y[i] - 1}] = u;
}
}
}
if(sz[f(0)] != n) {
assert(false);
return 0;
}
int m = e.size();
vector<int> used(m);
function<void(int)> dfs = [&](int i){
used[i] = 1;
for(auto [x, p1, p2] : edges[i]){
if(used[x]) continue;
p[x] = {p1, p2};
dfs(x);
}
};
for(auto [x, i] : mm){
if(used[i]) continue;
p[i] = x;
dfs(i);
}
for(int i=0;i<m;i++){
if(used[i]) continue;
p[i] = {edges[i].back()[1], edges[i].back()[2]};
edges[i].pop_back();
dfs(i);
}
vector<int> u(m), v(m), A(m), B(m);
for(int i=0;i<m;i++){
u[i] = e[i][0], v[i] = e[i][1];
A[i] = p[i][0], B[i] = p[i][1];
}
build(u, v, A, B);
return 1;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Runtime error |
9 ms |
9992 KB |
Execution killed with signal 6 |
4 |
Halted |
0 ms |
0 KB |
- |