Submission #893594

#	Time	Username	Problem	Language	Result	Execution time	Memory
893594		vjudge1	Road Construction (JOI21_road_construction)	C++17	0 / 100	10052 ms	327888 KiB

road_construction

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>

#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long

using namespace std;

int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}
	
const int N = 1e5 + 2, inf = 3e9, MAXN = 3e5;
int k;
struct pt {
	int x, y, id;
};

inline bool cmp_x (const pt & a, const pt & b) {
	return a.x < b.x || a.x == b.x && a.y < b.y;
}
 
inline bool cmp_y (const pt & a, const pt & b) {
	return a.y < b.y;
}
 
pt a[MAXN];
int mindist;
int ansa, ansb;
multiset <pair <int,int>> st;

inline void upd_ans (const pt & a, const pt & b) {
	int dist = abs(a.x-b.x) + abs(a.y-b.y);
	if(st.find({dist, a.id * b.id + min(a.id, b.id)}) != st.end()){
		return;
	}
	if((int)st.size() < k || (--st.end()) ->ff > dist){
		if((int)st.size() < k){
			st.insert({dist, a.id * b.id+ min(a.id, b.id)});
		}else{
			st.erase(--st.end());
			st.insert({dist, a.id * b.id+ min(a.id, b.id)});
		}
	}
	if((int)st.size() == k)
		mindist = (--st.end()) ->ff;
}

void rec (int l, int r) {
	if (r - l <= 3) {
		for (int i=l; i<=r; ++i)
			for (int j=i+1; j<=r; ++j)
				upd_ans (a[i], a[j]);
		sort (a+l, a+r+1, &cmp_y);
		return;
	}
 
	int m = (l + r) >> 1;
	int midx = a[m].x;
	rec (l, m),  rec (m+1, r);
	static pt t[MAXN];
	merge (a+l, a+m+1, a+m+1, a+r+1, t, &cmp_y);
	copy (t, t+r-l+1, a+l);
 
	int tsz = 0;
	for (int i=l; i<=r; ++i)
		if (abs (a[i].x - midx) < mindist) {
			for (int j=tsz-1; j>=0 && a[i].y - t[j].y < mindist; --j)
				upd_ans (a[i], t[j]);
			t[tsz++] = a[i];
		}
}

main(){
	iostream::sync_with_stdio(false);	
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n;
    cin >> n >> k;
    for(int i = 0; i < n; i++){
		cin >> a[i].x >> a[i].y;
		a[i].id = i + 1;
	}
	for(int i = n; i < n * 2; i++){
		a[i].x = inf * i;
		a[i].id = i + 1;
	}
    sort (a, a+n * 2, &cmp_x);
    mindist = 1e18;
	rec (0, n * 2-1);
	for(auto x : st){
		cout << x.ff <<"\n";
	}
	
	
}

Compilation message (stderr)

road_construction.cpp: In function 'bool cmp_x(const pt&, const pt&)':
road_construction.cpp:24:33: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   24 |  return a.x < b.x || a.x == b.x && a.y < b.y;
      |                      ~~~~~~~~~~~^~~~~~~~~~~~
road_construction.cpp: At global scope:
road_construction.cpp:78:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   78 | main(){
      | ^~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 7
• Subtask 4: 0 / 20
• Subtask 5: 0 / 27
• Subtask 6: 0 / 35