제출 #57050

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
57050		Plurm	Split the sequence (APIO14_sequence)	C++17	71 / 100	2052 ms	107420 KiB

sequence

#include <cstdio>
#include <cstring>
int a[100005];
long long dp[100005];
long long qs[100005];
int par[100005][256];
struct cst{
	long long M,C;
	int idx;
} L1[100005], L2[100005];
int prt[100005];
int ptr1,ptr2;
int csz1,csz2;
bool bad(cst x, cst y, cst z){
	return (x.M-y.M)*(z.C-x.C) <= (x.M-z.M)*(y.C-x.C);
}
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 && L1[ptr1+1].M*qs[i] + L1[ptr1+1].C > L1[ptr1].M*qs[i] + L1[ptr1].C) ptr1++;
			par[i][j] = L1[ptr1].idx;
			dp[i] = L1[ptr1].M*qs[i] + L1[ptr1].C;
			cst o = {qs[i],dp[i]-qs[i]*qs[i],i};
			while(csz2 >= 2 && bad(L2[csz2-2],L2[csz2-1],o)) csz2--;
			L2[csz2++] = o;
		}
		for(int i = 0; i < csz2; i++){
			L1[i] = L2[i];
		}
		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]);
	}
}

컴파일 시 표준 에러 (stderr) 메시지

sequence.cpp: In function 'int main()':
sequence.cpp:29:7: warning: unused variable 'id' [-Wunused-variable]
   int id;
       ^~
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