Submission #1276818

#	Time	Username	Problem	Language	Result	Execution time	Memory
1276818		Bui_Quoc_Cuong	Money (IZhO17_money)	C++20	0 / 100	7 ms	4168 KiB

money

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=a;i<=(int)b;i++)
#define FORD(i,a,b) for(int i=a;i>=(int)b;i--)
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(a) a.begin(),a.end()
#define BIT(mask,i) ((mask>>(i))&1)
#define MASK(a) (1LL<=((a)))
#define uni(v) sort(all(v)); v.resize(unique(all(v)) - v.begin())
#define pii pair <int, int>
#define vi vector <int> 
#define vl vector <ll>
template <class A,class B>
bool maximize(A &a, const B b)
{
    if(a < b){ a = b; return 1;} return 0;
}
template <class A,class B>
bool minimize(A &a, const B b)
{
    if(a > b){ a = b; return 1;} return 0;
}
const int maxn = 1e6 + 5;

int n;
int a[maxn];

namespace sub3
{
	vector <int> sorted[maxn];
	int dp[maxn];

	void solve()
	{
		for(int i = 1; i <= n; i++)
		{
			sorted[i] = sorted[i - 1];
			sorted[i].push_back(a[i]);
			sort(all(sorted[i]));
		}	
		memset(dp, 0x3f, sizeof dp);
		dp[0] = 0;
		for(int i = 1; i <= n; i++)
		{
			for(int j = i; j >= 1; j--)
			{
				if(j != i && a[j] > a[j + 1]) break;
				if(sorted[j - 1].empty() || sorted[j - 1][0] >= a[i] || sorted[j - 1].back() <= a[j] 
					|| sorted[j - 1][upper_bound(all(sorted[j - 1]), a[j]) - sorted[j - 1].begin()] >= a[i])
				{
					minimize(dp[i], dp[j - 1] + 1);
				}
			}
		}
		cout << dp[n];
	}
}

namespace sub4
{
	int le[maxn], ri[maxn], dp[maxn];

	void solve()
	{
		memset(dp, 0x3f, sizeof dp);
		dp[0] = 0;
		ri[0] = 2e9;
		set <int> se;
		for(int i = 1; i <= n; i++)
		{
			le[i] = (a[i] >= a[i - 1] ? le[i - 1] : i);
		}
		for(int i = 1; i < n; i++)
		{
			se.insert(a[i]);
			ri[i] = *se.upper_bound(a[i + 1]);
		}
		for(int i = 1; i <= n; i++)
		{
			int l = le[i], r = i, pos = i;
			while(l <= r)
			{
				int mid = (l + r) >> 1;
				if(ri[mid - 1] >= a[i]) pos = mid, r = mid - 1;
				else l = mid + 1;
			}
			dp[i] = dp[pos - 1] + 1;
		}
		cout << dp[n];
	}
}

void solve()
{
	cin >> n;
	for(int i = 1; i <= n; i++)
		cin >> a[i];
	// return sub3::solve();
	return sub4::solve();
}

signed main()
{
  ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);    
    #define kieuoanh "kieuoanh"
    if(fopen(kieuoanh".inp","r"))
    {
        freopen(kieuoanh".inp","r",stdin);
        freopen(kieuoanh".out","w",stdout);
    }
    int tst = 1; 
    // cin >> tst;
    while(tst--) solve();
    return 0;
}

Compilation message (stderr)

money.cpp: In function 'int main()':
money.cpp:112:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |         freopen(kieuoanh".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
money.cpp:113:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |         freopen(kieuoanh".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 16
• Subtask 3: 0 / 20
• Subtask 4: 0 / 55