Submission #1000291

#	Time	Username	Problem	Language	Result	Execution time	Memory
1000291		Hanksburger	Longest beautiful sequence (IZhO17_subsequence)	C++17	0 / 100	0 ms	348 KiB

subsequence

#include <bits/stdc++.h>
using namespace std;
int dp[100005], pre[100005], a[100005], k[100005], ind[260];
stack<int> s;
int bitCount(int x, int y)
{
    int cnt=0;
    for (int i=0; i<8; i++)
        if (x&y&(1<<i))
            cnt++;
    return cnt;
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, cur, mx=0;
    cin >> n;
    for (int i=1; i<=n; i++)
        cin >> a[i];
    for (int i=1; i<=n; i++)
        cin >> k[i];
    if (n<=5000)
    {
        for (int i=1; i<=n; i++)
        {
            dp[i]=1;
            for (int j=1; j<i; j++)
            {
                if (bitCount(a[i], a[j])==k[i])
                {
                    if (dp[i]<dp[j]+1)
                    {
                        dp[i]=dp[j]+1;
                        pre[i]=j;
                    }
                }
            }
            if (mx<dp[i])
            {
                mx=dp[i];
                cur=i;
            }
        }
    }
    else
    {
        for (int i=1; i<=n; i++)
        {
            dp[i]=1;
            for (int j=0; j<256; j++)
            {
                if (ind[j] && bitCount(a[i], j)==k[i])
                {
                    if (dp[i]<dp[ind[j]]+1)
                    {
                        dp[i]=dp[ind[j]]+1;
                        pre[i]=ind[j];
                    }
                }
            }
            if (mx<dp[i])
            {
                mx=dp[i];
                cur=i;
            }
            if (dp[ind[a[i]]]<dp[i])
                ind[a[i]]=i;
        }
    }
    
    cout << dp[cur] << '\n';
    while (cur)
    {
        s.push(cur);
        cur=pre[cur];
    }
    while (!s.empty())
    {
        cout << s.top() << ' ';
        s.pop();
    }
}

Compilation message (stderr)

subsequence.cpp: In function 'int main()':
subsequence.cpp:73:24: warning: 'cur' may be used uninitialized in this function [-Wmaybe-uninitialized]
   73 |     cout << dp[cur] << '\n';
      |                        ^~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 60