Submission #1036885

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036885		AmirAli_H1	Roller Coaster Railroad (IOI16_railroad)	C++17	64 / 100	68 ms	18920 KiB

railroad

// In the name of Allah

#include <bits/stdc++.h>
#include "railroad.h"
using namespace std;

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2e5 + 7;
const int maxs = 18;
const ll oo = 1e18 + 4;

int n; pll A[maxn];
ll dp[1 << maxs][maxs];
pll A1[maxn], A2[maxn];
int p[maxn], sz[maxn], num;

int get(int a) {
	return (p[a] == a) ? a : p[a] = get(p[a]);
}

void merge(int a, int b) {
	a = get(a); b = get(b);
	if (a == b) return ;
	if (sz[a] > sz[b]) swap(a, b);
	p[a] = b; sz[b] += sz[a]; sz[a] = 0; num--;
}

ll plan_roller_coaster(vector<int> s, vector<int> t) {
	n = len(s);
	for (int i = 0; i < n; i++) {
		A[i] = Mp(s[i], t[i]);
		A1[i] = Mp(s[i], i); A2[i] = Mp(t[i], i);
	}
	A1[n] = Mp(oo, n); A2[n] = Mp(-oo, n); n++;
	
	if (n < maxs) {
		for (int mask = 1; mask < (1 << n); mask++) {
	    	int x = mask;
	    	while (x > 0) {
	    		int j = __builtin_ctz(x);
				x ^= (1 << j);
				
				dp[mask][j] = oo;
	    		int y = mask ^ (1 << j);
	    		if (y == 0) dp[mask][j] = 0;
	    		while (y > 0) {
	    			int k = __builtin_ctz(y);
					y ^= (1 << k);
					dp[mask][j] = min(dp[mask][j], dp[mask ^ (1 << j)][k] + max(0ll, A[k].S - A[j].F));
				}
			}
		}
	    
	    ll ans = oo;
	    for (int j = 0; j < n; j++) ans = min(ans, dp[(1 << n) - 1][j]);
	    return ans;
	}
	else {
		sort(A1, A1 + n); sort(A2, A2 + n);
		iota(p, p + n, 0); fill(sz, sz + n, 1); num = n;
		for (int i = 0; i < n; i++) {
			if (A1[i].F >= A2[i].F) merge(A1[i].S, A2[i].S);
			else return 1;
			if (i + 1 < n && A1[i].F >= A2[i + 1].F) merge(A1[i].S, A2[i + 1].S);
		}
	    return (num != 1);
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 0 / 36