Submission #1012477

#	Time	Username	Problem	Language	Result	Execution time	Memory
1012477		akkshaysr	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	228 ms	17864 KiB

bridge

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define fr first
#define se second
#define rep(i,a,b) for(int i = a; i < (b); ++i)
#define rrep(i,a,b) for(int i = a; i > (b); --i)
#define sz(x) (int)(x).size()
#define all(x) (x).begin(),(x).end()
#define IN(i,l,r) (l<i&&i<r)
#define pb push_back
#define ones __builtin_popcountll
using namespace std;
using namespace __gnu_pbds;
template <class T>
using OSTree = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<long long> vll;
typedef long long ll;
int k,n;
vi home,office,ord;

void fill_cost(vll &sol){
	OSTree<pi> iset;
	sol[0] = abs(office[ord[0]] - home[ord[0]]);
	iset.insert({office[ord[0]],0});
	iset.insert({home[ord[0]],1});
	auto med = [&]() -> int {
		return iset.find_by_order((sz(iset)-1)/2)->fr;
	};
	int c = 2;
	rep(i,1,n){
		int old = med();
		iset.insert({home[ord[i]],c++});
		int neo = med();
		ll del = abs(home[ord[i]] - old) + (old - neo);
		old = neo;
		iset.insert({office[ord[i]],c++});
		neo = med();
		del += abs(office[ord[i]] - old);
		sol[i] = sol[i-1] + del;
	}
}

int main(){
	cin.tie(0)->sync_with_stdio(false);
	cin >> k >> n;
	ll no_cross = 0;
	rep(i,0,n){
		char p,q; int s,t; cin >> p >> s >> q >> t;
		if(p == q){
			no_cross += abs(t - s);
		}else{
			home.pb(s);
			office.pb(t);
		}
	}
	n = sz(home);
	if(n == 0){
		cout << no_cross << '\n'; return 0;
	}
	ord = vi(n,0);
	iota(all(ord),0);
	sort(all(ord),[](int a,int b){return home[a] + office[a] < home[b] + office[b];});
	vll pre(n,0), suf(n,0);
	fill_cost(pre);
	ll cross = pre[n-1];
	if(k == 1){
		cout << (no_cross + cross + n) << '\n'; return 0;
	}
	reverse(all(ord));
	fill_cost(suf);
	rep(i,1,n) cross = min(cross, pre[i-1] + suf[n-1-i]);
	cout << (no_cross + cross + n) << '\n';
}

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37