Submission #69110

#	Time	Username	Problem	Language	Result	Execution time	Memory
69110		Navick	Shortcut (IOI16_shortcut)	C++17	0 / 100	3 ms	568 KiB

shortcut

#include <bits/stdc++.h>
#include "shortcut.h"

#define F first
#define S second
#define pii pair<int, int>
#define pb push_back

using namespace std;

const int maxN = 510;

typedef long long ll;
typedef long double ld;

const ll oo = 1e18;

ll dp[maxN][maxN], pf[maxN], sf[maxN], ps[maxN];
ll h1[maxN][maxN], h2[maxN][maxN];

ll f[maxN], g[maxN];

long long find_shortcut(int n, std::vector<int> l, std::vector<int> d, int c)
{

	if(n >= maxN) cout << 1/0;

	for (int i=1; i<n; i++) ps[i] = ps[i - 1] + l[i - 1];

	for (int i=0; i<n; i++)
	{
		if(i) pf[i] = pf[i - 1] + l[i - 1];
		pf[i] = max(pf[i], (ll)d[i]);
	}

	for (int i=n-1; i>=0; i--)
	{
		if(i < n - 1) sf[i] = sf[i + 1] + l[i];
		sf[i] = max(sf[i], (ll)d[i]);
	}
	
	/*
	for (int len=1; len<=n; len++)
		for (int i=0; i+len<=n; i++)
		{
			int j = i + len - 1;
			if(len == 1) h1[i][i] = (ll)d[i] + ps[i], h2[i][i] = (ll)d[i] - ps[i];
			else
			{
				h1[i][j] = max(h1[i][j - 1], h1[i + 1][j]);
				h2[i][j] = max(h2[i][j - 1], h2[i + 1][j]);
			}
		}
	*/

	for (int i=0; i<n; i++)
	{
		if(i) f[i] = f[i - 1];
		if(i)f[i] = max(f[i], d[i] + l[i - 1] + pf[i - 1]);
	}

	for (int i=n-1; i>=0; i--)
	{
		if(i + 1 < n) g[i] = g[i + 1];
		if(i + 1 < n) g[i] = max(g[i], d[i] + l[i] + sf[i + 1]);
	}


	ll ans = 1e18;

	for (int i=0; i<n; i++) ans = max(ans, (ll)d[i]);
	
	for (int i=0; i<n; i++)
		for (int j=i+1; j<n; j++)
		{

			dp[i][j] = pf[i] + sf[j] + min((ll)c, ps[j] - ps[i]);

			dp[i][j] = max(dp[i][j], max(f[i], g[j]));
			
			ll len = ps[j] - ps[i] + c;
			
			for (int k=i; k<=j; k++)
			{
				ll lf = min(ps[k] - ps[i], len - ps[k] + ps[i]);
				dp[i][j] = max(dp[i][j], d[k] + lf + pf[i]);
				
				ll rg = min(ps[j] - ps[k], len - ps[j] + ps[k]);
				dp[i][j] = max(dp[i][j], d[k] + rg + sf[j]);
					

			}

			for (int k=i; k<=j; k++)
				for (int e=k+1; e<=j; e++)
					dp[i][j] = max(dp[i][j], d[k] + d[e] + min(ps[e] - ps[k], len - ps[e] + ps[k]));

			ans = min(ans, dp[i][j]);

		}

    return ans;
}

Compilation message (stderr)

shortcut.cpp: In function 'long long int find_shortcut(int, std::vector<int>, std::vector<int>, int)':
shortcut.cpp:26:25: warning: division by zero [-Wdiv-by-zero]
  if(n >= maxN) cout << 1/0;
                        ~^~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3