Submission #92339

#	Time	Username	Problem	Language	Result	Execution time	Memory
92339		Vardanyan	Split the sequence (APIO14_sequence)	C++14	50 / 100	2063 ms	43100 KiB

sequence

#pragma GCC optimize "-O3"
#include<bits/stdc++.h>

using namespace std;
const int N = 1000*100+5;
const long long INF = 1000000000000000000;
struct line{
    long long k,b;
    int id;
    line():k(0),b(0),id(0){}
    line(long long _k,long long _b,int _id):k(_k),b(_b),id(_id){}
};
struct node{
    node* l;
    node* r;
    line ln;
    node():l(NULL),r(NULL){}
};
long long f(line a,  long long x) {
    if(a.k == 0 && a.b == 0) return INF;
    return -(a.k*x+a.b);
}
const int maxn = 1000000000;
void add_line(line nw, node* v,int l = 0,int r = maxn){
    int m = (l+r)/2;
    bool lef = f(nw,l)<f(v->ln,l);
    bool mid = f(nw,m)<f(v->ln,m);
    if(mid){
        swap(v->ln,nw);
    }
    if(l == r) return;
    if(lef!=mid){
        if(v->l == NULL) v->l = new node();
        add_line(nw,v->l,l,m);
    }
    else{
        if(v->r == NULL) v->r = new node();
        add_line(nw,v->r,m+1,r);
    }
}
pair<long long,int> get(int x, node* v,int l = 0,int r = maxn){
        if(v == NULL) return {INF,0};
        if(l == r) return {f(v->ln,x),v->ln.id};
        int m = (l+r)/2;
        if(x<m){
            return min({f(v->ln,x),v->ln.id},get(x,v->l,l,m));
        }
        else return min({f(v->ln,x),v->ln.id},get(x,v->r,m+1,r));

}
void clean(node* v){
    if(v->l!=NULL) clean(v->l);
    if(v->r!=NULL) clean(v->r);
    v->ln = line(0,0,0);
}
void havasar(node* x,node* y){
    x->ln = y->ln;
    if(y->l!=NULL){
        if(x->l == NULL) x->l = new node();
        havasar(x->l,y->l);
    }
    if(y->r!=NULL){
        if(x->r == NULL) x->r = new node();
        havasar(x->r,y->r);
    }
}
int a[N];
long long pref[N];
pair<long long,int> dp[208][N];
int par[208][N];
int main()
{
    int n,k;
    scanf("%d%d",&n,&k);
    for(int i = 1;i<=n;i++) scanf("%d",&a[i]);
    for(int i = 1;i<=n;i++) pref[i] = pref[i-1]+a[i];
    node* old = new node();
    node* nold = new node();
    for(int kk = 1;kk<=k;kk++){
        for(int i = kk+1;i<=n;i++){
            if(kk == 1){
                for(int j = dp[kk-1][i].second;j<i;j++){
                    if(dp[kk-1][j].first+(pref[i]-pref[j])*pref[j]>=dp[kk][i].first){
                        dp[kk][i].first = dp[kk-1][j].first+(pref[i]-pref[j])*pref[j];
                        dp[kk][i].second = j;
                    }
                }
                line now = line({pref[i],dp[kk][i].first-pref[i]*pref[i],i});
                add_line(now,nold);
                continue;
            }
            pair<long long,int> u = get(pref[i],old);
            dp[kk][i].first = -u.first;
            dp[kk][i].second = u.second;
            line now = line({pref[i],dp[kk][i].first-pref[i]*pref[i],i});
            add_line(now,nold);
        }
        havasar(old,nold);
        clean(nold);
    }
    printf("%lld\n",dp[k][n].first);
    int kk = k;
    int nn = n;
    while(kk>0){
        printf("%d\n",dp[kk][nn].second);
        nn = dp[kk][nn].second;
        kk--;
    }
    printf("\n");
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:74:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&k);
     ~~~~~^~~~~~~~~~~~~~
sequence.cpp:75:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i = 1;i<=n;i++) scanf("%d",&a[i]);
                             ~~~~~^~~~~~~~~~~~

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