Submission #955098

#	Time	Username	Problem	Language	Result	Execution time	Memory
955098		Otalp	Sequence (APIO23_sequence)	C++17	28 / 100	2077 ms	36720 KiB

sequence

#include "sequence.h"
#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define pb push_back
#define ff first
#define ss second

int a[500100];
int s1[500100], s2[500100], c[500100];
struct node{
    pii x={1e9, -1e9};
    node *l = nullptr, *r = nullptr;
    node(){}
};
 
node *t = new node();
 
 
void upd(node *v, int l, int r, int pos, int x){
    if(l == r){
        v -> x = {min(v -> x.ff, x), max(v -> x.ss, x)};
        return;
    }
    int mid = floor(((double)l + (double)r) / 2);
    if(mid >= pos){
        if(!v -> l) v->l = new node();
        upd(v -> l, l, mid, pos, x);
    }
    else{
        if(!v -> r) v->r = new node();
        upd(v->r, mid+1, r, pos, x);
    }
    v -> x = {1e9, -1e9};
    if(v -> l) v -> x = {min(v -> x.ff, v -> l -> x.ff), max(v -> x.ss, v -> l -> x.ss)};
    if(v -> r) v -> x = {min(v -> x.ff, v -> r -> x.ff), max(v -> x.ss, v -> r -> x.ss)};
}
 
pii get(node *v, int l, int r, int L, int R){
    if(r < L or R < l){
        return {1e9, -1e9};
    }
    if(L <= l and r <= R){
        return v -> x;
    }
    int mid=floor(((double)l + (double)r) / 2);
    pii x = {1e9, -1e9};
    if(v -> l){
        pii k = get(v -> l, l, mid, L, R);
        x = {min(x.ff, k.ff), max(x.ss, k.ss)};
    }

    if(v -> r){
        pii k = get(v -> r, mid + 1, r, L, R);
        x = {min(x.ff, k.ff), max(x.ss, k.ss)};
    }
    return x;
}


int sequence(int n, vector<int> A) {
    int ans = 0;
    for(int i=1; i<=n; i++){
        a[i] = A[i - 1];
    }
    for(int x=1; x<=n; x++){

        vector<pii> q;
        int mn=0, mx=0, sum=0;
        for(int i=1; i<=n; i++){
            if(a[i] == x){
                q.pb({mn, mx});
                mn = 1e9;
                mx = -1e9;
            }
            if(a[i] > x){
                sum += 1;
            }
            if(a[i] < x){
                sum -= 1;
            }
            mn = min(mn, sum);
            mx = max(mx, sum);
        }
        q.pb({mn, mx});
        vector<pair<pii, int> > zap;
        for(int i=0; i<q.size(); i++){
            zap.pb({{q[i].ss + i, q[i].ff-i}, i});
        }
        vector<pair<pii, int> > h;
        for(int i=0; i<q.size(); i++){
            h.pb({{q[i].ff+i, q[i].ss-i}, i});
        }
        sort(h.begin(), h.end());
        sort(zap.begin(), zap.end());
        int ls = 0;
        t = new node();
        for(int i=0; i<zap.size(); i++){
            int L=zap[i].ff.ff, R=zap[i].ff.ss;
            while(ls < h.size() and h[ls].ff.ff <= L){
                upd(t, -n, n, h[ls].ff.ss, h[ls].ss);
                ls++;
            }
            pii d = get(t, -n, n, R, n);
            ans = max(ans, max(zap[i].ss - d.ff, d.ss - zap[i].ss));
        }
    }
    return ans;
}

Compilation message (stderr)

sequence.cpp: In function 'int sequence(int, std::vector<int>)':
sequence.cpp:87:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   87 |         for(int i=0; i<q.size(); i++){
      |                      ~^~~~~~~~~
sequence.cpp:91:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |         for(int i=0; i<q.size(); i++){
      |                      ~^~~~~~~~~
sequence.cpp:98:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         for(int i=0; i<zap.size(); i++){
      |                      ~^~~~~~~~~~~
sequence.cpp:100:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |             while(ls < h.size() and h[ls].ff.ff <= L){
      |                   ~~~^~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18