Submission #1061795

#	Time	Username	Problem	Language	Result	Execution time	Memory
1061795		Andrey	Sequence (APIO23_sequence)	C++17	41 / 100	2078 ms	64592 KiB

sequence

#include "sequence.h"
#include<bits/stdc++.h>
using namespace std;

vector<int> haha[500001];
vector<pair<int,int>> seg(2500001);
vector<int> wow(2500001);

void upd(int l, int r, int ql, int qr, int x, int br) {
    if(l == ql && r == qr) {
        wow[x]+=br;
        seg[x] = {seg[x].first+br,seg[x].second+br};
        return;
    }
    int mid = (l+r)/2;
    if(qr <= mid) {
        upd(l,mid,ql,qr,x*2,br);
    }
    else if(ql > mid) {
        upd(mid+1,r,ql,qr,x*2+1,br);
    }
    else {
        upd(l,mid,ql,mid,x*2,br);
        upd(mid+1,r,mid+1,qr,x*2+1,br);
    }
    seg[x] = {max(seg[x*2].first,seg[x*2+1].first)+wow[x],min(seg[x*2].second,seg[x*2+1].second)+wow[x]};
}

pair<int,int> calc(int l, int r, int ql, int qr, int x) {
    if(ql == l && qr == r) {
        return seg[x];
    }
    int mid = (l+r)/2;
    pair<int,int> a,b;
    if(qr <= mid) {
        a = calc(l,mid,ql,qr,x*2);
        return {a.first+wow[x],a.second+wow[x]};
    }
    else if(ql > mid) {
        a = calc(mid+1,r,ql,qr,x*2+1);
        return {a.first+wow[x],a.second+wow[x]};
    }
    else {
        a = calc(l,mid,ql,mid,x*2);
        b = calc(mid+1,r,mid+1,qr,x*2+1);
        return {max(a.first,b.first)+wow[x],min(a.second,b.second)+wow[x]};
    }
}

int sequence(int n, std::vector<int> a) {
    for(int i = 0; i < a.size(); i++) {
        haha[a[i]].push_back(i+1);
    }
    for(int i = 1; i <= n; i++) {
        upd(0,n,i,n,1,-1);
    }
    int ans = 1;
    for(int i = 1; i <= n; i++) {
        for(int v: haha[i]) {
            upd(0,n,v,n,1,1);
        }
        for(int j = 0; j < haha[i].size(); j++) {
            for(int k = j+1; k < haha[i].size(); k++) {
                int l = haha[i][j],r = haha[i][k];
                pair<int,int> a = calc(0,n,0,l-1,1),b = calc(0,n,r,n,1);
                int big = b.first-a.second,sm = b.second-a.first;
                if(sm <= k-j+1 && big >= -(k-j+1)) {
                    ans = max(ans,k-j+1);
                }
            }
        }
        for(int v: haha[i]) {
            upd(0,n,v,n,1,1);
        }
    }
    return ans;
}

Compilation message (stderr)

sequence.cpp: In function 'int sequence(int, std::vector<int>)':
sequence.cpp:51:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for(int i = 0; i < a.size(); i++) {
      |                    ~~^~~~~~~~~~
sequence.cpp:62:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         for(int j = 0; j < haha[i].size(); j++) {
      |                        ~~^~~~~~~~~~~~~~~~
sequence.cpp:63:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |             for(int k = j+1; k < haha[i].size(); k++) {
      |                              ~~^~~~~~~~~~~~~~~~

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