Submission #6892

#	Time	Username	Problem	Language	Result	Execution time	Memory
6892		woqja125	Split the sequence (APIO14_sequence)	C++98	0 / 100	0 ms	85852 KiB

sequence

#include<stdio.h>
int dat[100001], s[100001];
long long dp[2][100001];
int p[210][100001];
int stk[100001], b;
inline long long getY(long long *D, int x)
{
	return D[x] - 1ll*s[x]*s[x];
}
inline bool cmp(long long *D, int z)
{
	int x, y;
	x = stk[b-1];
	y = stk[b];

	return (getY(D, y)-getY(D, x))*(s[y]-s[z]) > (getY(D, z)-getY(D, y)) *(s[x]-s[y]);
}
int main()
{
	int n, k;
	int i, j, l;
	scanf("%d%d", &n, &k); k++;
	for(i=1; i<=n; i++)
	{
		scanf("%d", &dat[i]);
		s[i] = s[i-1] + dat[i];
	}
	for(i=0; i<=1; i++)for(j=0; j<=n; j++) dp[i][j]=-1;
	for(j=0; j<=n; j++)
	{
		dp[1][j] = 0;
	}
	for(i=2; i<=k; i++)
	{
		for(j=0; j<=n; j++) dp[i%2][j]=-1;
		long long *D = dp[(i-1)%2];
		b = -1;
		int x=0;
		stk[++b] = 0; stk[++b] = 1;
		for(l=2; l<=n; l++)
		{
			if(x>b) x = b;
			while(x < b && (getY(D, stk[x]) -getY(D, stk[x+1])) < 1ll*(s[stk[x+1]] - s[stk[x]])*s[l] ) x++;
			dp[i%2][l] = D[stk[x]] - 1ll*s[stk[x]]*s[stk[x]] + 1ll*s[stk[x]]*s[l];
			p[i][l] = stk[x];
			while( cmp(D, l) ) b--;
			stk[++b] = l;
		}
		for(l; j<=n; j++)
		{
			long long max = -1;
			int x = -1;
			p[i][j] = x;
			dp[i%2][j] = max;
		}
	}
	printf("%lld\n", dp[k%2][n]);
	int x = n;
	for(int i=k; i>1; i--)
	{
		x = p[i][x];
		printf("%d ", x);
	}
	return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29