Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <memory.h>
#include <queue>
#include <cstdio>
#include <cstdlib>
#include <map>
#include <cmath>
using namespace std;

#define rep(i, n) for(int i = 0; i< n; i++)
typedef long long ll;
typedef pair<int, int> P;

int dp[310][310];
P par[310][310];

int main(){
  string s;
  while(cin >> s && s != "#END"){
    int n = s.size();
    string res;
    for(int i = 1; i < n; i++){
      string a(s.begin(), s.begin() + i);
      string b(s.begin() + i, s.end());
      if(max(a.size() < b.size()) <= res.size()) continue;

      memset(dp, 0, sizeof(dp));
      memset(par, -1, sizeof(par));


      rep(i, (int)a.size() + 1)rep(j, (int)b.size() + 1){
	
	if(i > 0 && dp[i][j] < dp[i-1][j]){
	  dp[i][j] = dp[i-1][j];
	  par[i][j] = P(i- 1, j);
	}
	if(j > 0 && dp[i][j] < dp[i][j-1]){
	  dp[i][j] = dp[i][j-1];
	  par[i][j] = P(i, j-1);
	}
	if(i > 0 && j > 0 && a[i-1] == b[j-1] && dp[i][j] < dp[i-1][j-1] + 1){
	  dp[i][j] = dp[i-1][j-1] + 1;
	  par[i][j] = P(i - 1, j - 1);
	}
      }
      string lss;
      int x = (int)a.size();
      int y = (int)b.size();
      while(x != -1){
	P p = par[x][y];
	if(x - p.first == 1 && y - p.second == 1) lss.push_back(a[x-1]);
	x = p.first;
	y = p.second;
      }
      reverse(lss.begin(), lss.end());
      if(lss.size() > res.size()) res = lss;
    }
    cout << res << endl;
  }
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:28:13: error: no matching function for call to 'max(bool)'
   28 |       if(max(a.size() < b.size()) <= res.size()) continue;
      |          ~~~^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 1 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   template argument deduction/substitution failed:
a.cc:28:13: note:   mismatched types 'std::initializer_list<_Tp>' and 'bool'
   28 |       if(max(a.size() < b.size()) <= res.size()) continue;
      |          ~~~^~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   candidate expects 2 arguments, 1 provided