Submission #1075440

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075440		Muhammad_Aneeq	Radio Towers (IOI22_towers)	C++17	15 / 100	4064 ms	8668 KiB

towers

#include <vector>
#include <algorithm>
#include <cmath>
#include <iostream>
using namespace std;
int const MAXN=1e5+10,LG=18;
int sp[MAXN][LG]={};
int n;
int dp[MAXN]={};
int a[MAXN]={};
bool uni=1;
int k=0;
void init(int N,vector<int> H)
{
	for (int i=0;i<N;i++)
		sp[i][0]=H[i],a[i]=H[i];
	for (int i=1;(1<<i)<=N;i++)
		for (int j=0;j+(1<<i)-1<N;j++)
			sp[j][i]=max(sp[j][i-1],sp[j+(1<<(i-1))][i-1]);
	n=N;
	for (int i=0;i+1<n;i++)
	{
		if (a[i]<a[i+1])
			k=i+1;
		else
			break;
	}
	for (int i=k;i+1<n;i++)
	{
		if (a[i]>a[i+1])
			continue;
		else
		{
			uni=0;
			break;
		}
	}
}
int get(int l,int r)
{
	if (l>r)
		return -1;
	int lg=log2(r-l+1);
	return max(sp[l][lg],sp[r-(1<<lg)+1][lg]);
}
int max_towers(int L, int R, int D)
{
	if (uni)
	{
		if (k>L&&k<R&&max(a[L],a[R])+D<=a[k])
				return 2;
		return 1;
	}
	int i=L,j=R;
	if (R-L+1<3)
	{
		return R-L+1;
	}
	int ans=0;
	for (int i=L;i<=R;i++)
	{
		dp[i]=1;
		for (int j=i-2;j>=L;j--)
		{
			int z=get(j+1,i-1);
			if (z>=max(a[i],a[j])+D)
				dp[i]=max(dp[i],dp[j]+1);
		}
		ans=max(ans,dp[i]);
	}
	return ans;
}

Compilation message (stderr)

towers.cpp: In function 'int max_towers(int, int, int)':
towers.cpp:54:6: warning: unused variable 'i' [-Wunused-variable]
   54 |  int i=L,j=R;
      |      ^
towers.cpp:54:10: warning: unused variable 'j' [-Wunused-variable]
   54 |  int i=L,j=R;
      |          ^

• Subtask 1: 4 / 4
• Subtask 2: 11 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23