Submission #127102

#	Time	Username	Problem	Language	Result	Execution time	Memory
127102		liwi	Split the sequence (APIO14_sequence)	C++11	100 / 100	1457 ms	81988 KiB

sequence

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;

#define scan(x) do{while((x=getchar())<'0'); for(x-='0'; '0'<=(_=getchar()); x=(x<<3)+(x<<1)+_-'0');}while(0)
char _;
#define complete_unique(a) a.erase(unique(a.begin(),a.end()),a.end())
#define all(a) a.begin(),a.end()
#define println printf("\n");
#define readln(x) getline(cin,x);
#define pb push_back
#define endl "\n"
#define INT_INF 0x3f3f3f3f
#define LL_INF 0x3f3f3f3f3f3f3f3f
#define MOD 1000000007
#define mp make_pair
#define fastio cin.tie(0); cin.sync_with_stdio(0);

#define MAXN 100005
#define MAXK 205

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef unordered_map<int,int> umii;
typedef pair<int,int> pii;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef pair<int,pii> triple;
typedef int8_t byte;

mt19937 g1(time(0));

int randint(int a, int b){return uniform_int_distribution<int>(a, b)(g1);}
ll randlong(ll a,ll b){return uniform_int_distribution<long long>(a, b)(g1);}

ll gcd(ll a, ll b){return b == 0 ? a : gcd(b, a % b);}
ll lcm(ll a, ll b){return a*b/gcd(a,b);}
ll fpow(ll  b, ll exp, ll mod){if(exp == 0) return 1;ll t = fpow(b,exp/2,mod);if(exp&1) return t*t%mod*b%mod;return t*t%mod;}
ll divmod(ll i, ll j, ll mod){i%=mod,j%=mod;return i*fpow(j,mod-2,mod)%mod;}

int len,K,arr[MAXN],par[MAXK][MAXN],ck,lst;
ll dp[2][MAXN],psa[MAXN];

void solve(int l, int r, int lp, int rp){
	if(l > r) return;
	if(lp == rp){
		for(int i=l; i<=r; i++){
			ll cst = dp[!lst][lp]+(psa[i]-psa[lp])*psa[lp];
			dp[lst][i] = cst;
			par[ck][i] = lp;
		}
		return;
	}
	int mid = (l+r)/2, np = lp, lim = min(mid-1,rp);
	ll cur_best = dp[lst][mid] = LLONG_MIN;
	for(int i=lp; i<=lim; i++){
		ll cst = dp[!lst][i]+(psa[mid]-psa[i])*psa[i];
		if(cst > cur_best){
			cur_best = cst;
			np = i;
		}
	}
	dp[lst][mid] = cur_best;
	par[ck][mid] = np;

	solve(l,mid-1,lp,np);
	solve(mid+1,r,np,rp);
}

int main(){
	scanf("%d %d",&len,&K); K++;
	for(int i=1; i<=len; i++){
		scanf(" %d",&arr[i]);
		psa[i] = psa[i-1]+arr[i];
	}
	for(ck=2; ck<=K; ck++){
		lst = !lst;
		solve(ck,len,ck-1,len);
	}
	printf("%lld\n",dp[lst][len]);
	vector<int> v;
	int curr = len;
	for(int i=K; i>=1; i--){
		if(i < K) v.pb(curr);
		curr = par[i][curr];
	}
	for(int i=(int)v.size()-1; i>=0; i--)
		printf("%d ",v[i]);
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:76:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&len,&K); K++;
  ~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:78:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf(" %d",&arr[i]);
   ~~~~~^~~~~~~~~~~~~~~

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