Language: C++

#include<iostream>
#include<algorithm>

using namespace std;

short nails[5001][5001];

int main(void){

  int n,m,a,b,x;
 
  cin >> n >> m;

  for(int i=0;i<m;i++){
    cin >> a >> b >> x;
    nails[a][b]=x+1;
  }

  for(int i=1;i<=n;i++){
    for(int j=1;j<=i;j++){
      nails[i][j]=(short)max((short)nails[i][j],(short)max((short)nails[i-1][j-1],(short)nails[i-1][j])-(short)1);      
    }
  }

  int cnt=0;
  for(int i=1;i<=n;i++)
    for(int j=1;j<=i;j++)
      if(nails[i][j]>0)cnt++;
     
  cout << cnt << endl;

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:29: error: no matching function for call to 'max(short int, int)'
   21 |       nails[i][j]=(short)max((short)nails[i][j],(short)max((short)nails[i-1][j-1],(short)nails[i-1][j])-(short)1);
      |                          ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:   template argument deduction/substitution failed:
a.cc:21:29: note:   deduced conflicting types for parameter 'const _Tp' ('short int' and 'int')
   21 |       nails[i][j]=(short)max((short)nails[i][j],(short)max((short)nails[i-1][j-1],(short)nails[i-1][j])-(short)1);
      |                          ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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, 2 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:   candidate expects 1 argument, 2 provided
/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:   template argument deduction/substitution failed:
a.cc:21:29: note:   mismatched types 'std::initializer_list<_Tp>' and 'short int'
   21 |       nails[i][j]=(short)max((short)nails[i][j],(short)max((short)nails[i-1][j-1],(short)nails[i-1][j])-(short)1);
      |                          ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~