Submission #756994

#	Time	Username	Problem	Language	Result	Execution time	Memory
756994		Valters07	Sequence (APIO23_sequence)	C++17	0 / 100	71 ms	4208 KiB

sequence

#include <bits/stdc++.h>
#include "sequence.h"
#define ll long long
#define pb push_back
#define fi first
#define se second
using namespace std;
int sequence(int n, vector<int> a)
{
    int peak = 0;
    while(peak+1<n&&a[peak]<=a[peak+1])
        peak++;
    int res = 1, l = 0, r;
    for(int i = 1;i<n;i++)
        if(a[i]!=a[i-1])
            l=i;
        else
            res=max(res,i-l+1);
    l = r = peak;
    while(l>0&&a[l-1]==a[l])
        l--;
    while(r<n-1&&a[r+1]==a[r])
        r++;
    while(l>0&&r<n-1)
    {
        if(a[l]>a[r])
            l--;
        else if(a[l]<a[r])
            r++;
        else
            l--,
            r++;
        int c1 = 1, c2 = 1;
        while(l>0&&a[l-1]==a[l])
            c1++,
            l--;
        while(r<n-1&&a[r+1]==a[r])
            c2++,
            r++;
        if(a[l]==a[r])
        {
            int mi = l+(n-r-1), cur = c1+c2, mx = n-mi-cur;
            if(abs(mi-mx)<=cur)
                res=max(res,cur);
        }
    }
    return res;
}

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