Language: C++

#include<iostream>
#include<vector>
#include<cmath>
using namespace std;

#define rep(i,N) for(int i,i<(int)N,i++)
bool joken(int a,int b,int c);

int main()
{
  int N;
  cin>>N;
  vector<int> L(N,0);
  int number=0;	//条件に合致する組み合わせの数
  
  rep(ni,N)
  {
    cin>>L(ni);
  }
  
  if(N<3)
  {
    cout<<0<<endl;
    return 0;
  }
  
  rep(ni,N-2)
  {
    for(nj=ni+1,nj<N-1;nj++)
    {
      for(nk=nj+1,nk<N;nk++)
      {
        if((joken(L(ni),L(nj),L(nk))&&
            (joken(L(nj),L(nk),L(ni))&&
             (joken(L(nk),L(ni),L(nj)))
             number++;
      }
    }
  }
  return 0;
}

bool joken(int a,int b,int c)
{
  if((a+b)>c)
    return true;
  else
    false;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:29: error: expected ';' before '<' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                             ^
a.cc:16:3: note: in expansion of macro 'rep'
   16 |   rep(ni,N)
      |   ^~~
a.cc:6:29: error: expected primary-expression before '<' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                             ^
a.cc:16:3: note: in expansion of macro 'rep'
   16 |   rep(ni,N)
      |   ^~~
a.cc:6:40: error: expected ';' before ')' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                                        ^
a.cc:16:3: note: in expansion of macro 'rep'
   16 |   rep(ni,N)
      |   ^~~
a.cc:18:11: error: no match for call to '(std::vector<int>) (int&)'
   18 |     cin>>L(ni);
      |          ~^~~~
a.cc:6:29: error: expected ';' before '<' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                             ^
a.cc:27:3: note: in expansion of macro 'rep'
   27 |   rep(ni,N-2)
      |   ^~~
a.cc:6:29: error: expected primary-expression before '<' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                             ^
a.cc:27:3: note: in expansion of macro 'rep'
   27 |   rep(ni,N-2)
      |   ^~~
a.cc:6:40: error: expected ';' before ')' token
    6 | #define rep(i,N) for(int i,i<(int)N,i++)
      |                                        ^
a.cc:27:3: note: in expansion of macro 'rep'
   27 |   rep(ni,N-2)
      |   ^~~
a.cc:29:9: error: 'nj' was not declared in this scope; did you mean 'ni'?
   29 |     for(nj=ni+1,nj<N-1;nj++)
      |         ^~
      |         ni
a.cc:29:28: error: expected ';' before ')' token
   29 |     for(nj=ni+1,nj<N-1;nj++)
      |                            ^
      |                            ;
a.cc:31:11: error: 'nk' was not declared in this scope; did you mean 'ni'?
   31 |       for(nk=nj+1,nk<N;nk++)
      |           ^~
      |           ni
a.cc:31:28: error: expected ';' before ')' token
   31 |       for(nk=nj+1,nk<N;nk++)
      |                            ^
      |                            ;
a.cc:33:20: error: no match for call to '(std::vector<int>) (int&)'
   33 |         if((joken(L(ni),L(nj),L(nk))&&
      |                   ~^~~~
a.cc:34:33: error: no match for call to '(std::vector<int>) (int&)'
   34 |             (joken(L(nj),L(nk),L(ni))&&
      |                                ~^~~~
a.cc:35:28: error: no match for call to '(std::vector<int>) (int&)'
   35 |              (joken(L(nk),L(ni),L(nj)))
      |                           ~^~~~
a.cc:35:40: error: expected ')' before 'number'
   35 |              (joken(L(nk),L(ni),L(nj)))
      |                                        ^
      |                                        )
   36 |              number++;
      |              ~~~~~~                     
a.cc:34:13: note: to match this '('
   34 |             (joken(L(nj),L(nk),L(ni))&&
      |             ^
a.cc:36:22: error: expected ')' before ';' token
   36 |              number++;
      |                      ^
      |                      )
a.cc:33:12: note: to match this '('
   33 |         if((joken(L(ni),L(nj),L(nk))&&
      |            ^
a.cc:36:22: error: expected ')' before ';' token
   36 |              number++;
      |                      ^
      |                      )
a.cc:33:11: note: to match this '('
   33 |         if((joken(L(ni),L(nj),L(nk))&&
      |           ^
a.cc: In function 'bool joken(int, int, int)':
a.cc:49:1: warning: control reaches end of non-void function [-Wreturn-type]
   49 | }
      | ^