Submission #57041

#	Time	Username	Problem	Language	Result	Execution time	Memory
57041		Plurm	Split the sequence (APIO14_sequence)	C++17	71 / 100	2063 ms	132096 KiB

sequence

#include <cstdio>
#include <cstring>
#define bad(x,y,z) ((C[y]-C[x])*(M[x]-M[z]) >= (C[z]-C[x])*(M[x]-M[y]))
int a[100005];
long long dp[100005];
long long qs[100005];
int par[100005][256];
long long M1[100005];
long long C1[100005];
int idx1[100005];
long long M2[100005];
long long C2[100005];
int idx2[100005];
int prt[100005];
int ptr1,ptr2;
int csz1,csz2;
int main(){
	int n,k;
	scanf("%d%d",&n,&k);
	k++;
	csz1++;
	for(int i = 1; i <= n; i++){
		scanf("%d",a+i);
		qs[i] = qs[i-1] + (long long)a[i];
		dp[i] = -1e16;
	}
	for(int j = 1; j <= k; j++){
		csz2 = ptr2 = 0;
		int id;
		for(int i = j; i <= n; i++){
			if(ptr1 >= csz1) ptr1 = csz1-1;
			while(ptr1 < csz1-1 && M1[ptr1+1]*qs[i] + C1[ptr1+1] > M1[ptr1]*qs[i] + C1[ptr1]) ptr1++;
			id = ptr1;
			par[i][j] = idx1[id];
			dp[i] = M1[id]*qs[i] + C1[id];
			while(csz2 >= 2 && (C2[csz2-1]-C2[csz2-2])*(M2[csz2-2]-qs[i]) >= (dp[i]-qs[i]*qs[i]-C2[csz2-2])*(M2[csz2-2]-M2[csz2-1])) csz2--;
			M2[csz2] = qs[i];
			C2[csz2] = dp[i] - qs[i]*qs[i];
			idx2[csz2] = i;
			csz2++;
		}
		memmove(M1,M2,csz2*sizeof(long long));
		memmove(C1,C2,csz2*sizeof(long long));
		memmove(idx1,idx2,csz2*sizeof(long long));
		csz1 = csz2;
		ptr1 = ptr2;
	}
	printf("%lld\n",dp[n]);
	int x = n;
	csz1 = 0;
	for(int j = k; j > 1; j--){
		x = par[x][j];
		prt[csz1++] = x;
	}
	for(int i = 0; i < csz1; i++){
		printf("%d ",prt[i]);
	}
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:19:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&k);
  ~~~~~^~~~~~~~~~~~~~
sequence.cpp:23:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",a+i);
   ~~~~~^~~~~~~~~~

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