Submission #7663

#	Time	Username	Problem	Language	Result	Execution time	Memory
7663		imsifile	Split the sequence (APIO14_sequence)	C++98	100 / 100	604 ms	84764 KiB

sequence

#include<stdio.h>
#define sq(a) ((a)*(a))
#define sik(l,x) (-(l.a)*(x)+(l.b))

typedef long long lld;

struct lin {
	int ix;
	lld a, b; // -ax+b
}stk[100100], im;

int n, k, di[100100][202], scn;
lld ba[100100], dy[100100][2];

int main(){
	int i, i2, j, t=1;
	scanf("%d%d", &n, &k);
	for(i=1; i<=n; i++){
		scanf("%lld", &ba[i]), ba[i]+=ba[i-1];
		dy[i][0]=sq(ba[i]);
	}
	for(j=1; j<=k; j++){
		im.a=2*ba[j], im.b=dy[j][1-t]+sq(ba[j]), im.ix=j;
		stk[0]=im, scn=1;
		for(i=1; i<=j; i++)dy[i][t]=0;
		for(i=j+1, i2=0; i<=n; i++){
			for(; i2<scn-1; i2++){
				if(sik(stk[i2],ba[i])<sik(stk[i2+1],ba[i]))break;
			}
			di[i][j]=stk[i2].ix, dy[i][t]=sq(ba[i])+sik(stk[i2],ba[i]);
			im.ix=i, im.a=2*ba[i], im.b=dy[i][1-t]+sq(ba[i]);
			for(; scn; scn--){
				if(stk[scn-1].b>=im.b)continue;
				if((stk[scn-1].b-stk[scn-2].b)*(im.a-stk[scn-2].a)<(im.b-stk[scn-2].b)*(stk[scn-1].a-stk[scn-2].a))break;
			}
			stk[scn++]=im;
			if(i2>=scn)i2=scn-1;
		}
		t=1-t;
	}
	printf("%lld\n", (sq(ba[n])-dy[n][1-t])/2);
	for(i=n, j=k; j>0; j--)printf("%d ", di[i][j]), i=di[i][j];
	return 0;
}

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