longest_commmon_subsequence_of_three_sequences

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
int lcs3(vector<int> &a, vector<int> &b, vector<int> &c)
{
  vector<vector<vector<int>>> dp(a.size() + 1, vector<vector<int>>(b.size() + 1, vector<int>(c.size() + 1, 0)));
  for (int i = 1; i <= a.size(); i++)
  {
    for (int j = 1; j <= b.size(); j++)
    {
      for (int k = 1; k <= c.size(); k++)
      {
        if (a[i - 1] == b[j - 1] && b[j - 1] == c[k - 1])
          dp[i][j][k] = 1 + dp[i - 1][j - 1][k - 1];
        else
        {
          dp[i][j][k] = max(dp[i - 1][j][k], max(dp[i][j - 1][k], dp[i][j][k - 1]));
        }
      }
    }
  }
  return dp[a.size()][b.size()][c.size()];
}

int main()
{
  size_t an;
  std::cin >> an;
  vector<int> a(an);
  for (size_t i = 0; i < an; i++)
  {
    std::cin >> a[i];
  }
  size_t bn;
  std::cin >> bn;
  vector<int> b(bn);
  for (size_t i = 0; i < bn; i++)
  {
    std::cin >> b[i];
  }
  size_t cn;
  std::cin >> cn;
  vector<int> c(cn);
  for (size_t i = 0; i < cn; i++)
  {
    std::cin >> c[i];
  }
  std::cout << lcs3(a, b, c) << std::endl;
}