Language: C++

#include<iostream>
#include<vector>
usinga namespace std;

int main(){
	int h,w,n,current=0;
	cin >>h >>w >>n ;	
	int a;
	vector<vector<int>>c(h,vector<int>(w));

	for(int i=0;i<n;i++){
		cin >>a ;
		for(int j=0;j<a;j++){
			if((current/w)%2==0) c[current/w][current%w]=i+1;
			else c[current/w][w-(current%w)-1]=i+1;
			current++;
		}
	}

	for(int i=0;i<h;i++){
		for(int j=~;j<w;j++){
			if(j==w-1) cout<<c[i][j]<<endl;
			else cout<<c[i][j]<<" ";
		}
	}


	return 0;
}


Compiler output:
a.cc:3:1: error: 'usinga' does not name a type
    3 | usinga namespace std;
      | ^~~~~~
a.cc: In function 'int main()':
a.cc:7:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |         cin >>h >>w >>n ;
      |         ^~~
      |         std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:9:9: error: 'vector' was not declared in this scope
    9 |         vector<vector<int>>c(h,vector<int>(w));
      |         ^~~~~~
a.cc:9:9: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/14/vector:93:13: note:   'std::pmr::vector'
   93 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
a.cc:9:23: error: expected primary-expression before 'int'
    9 |         vector<vector<int>>c(h,vector<int>(w));
      |                       ^~~
a.cc:14:46: error: 'c' was not declared in this scope
   14 |                         if((current/w)%2==0) c[current/w][current%w]=i+1;
      |                                              ^
a.cc:15:30: error: 'c' was not declared in this scope
   15 |                         else c[current/w][w-(current%w)-1]=i+1;
      |                              ^
a.cc:21:28: error: expected primary-expression before ';' token
   21 |                 for(int j=~;j<w;j++){
      |                            ^
a.cc:22:36: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   22 |                         if(j==w-1) cout<<c[i][j]<<endl;
      |                                    ^~~~
      |                                    std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:22:42: error: 'c' was not declared in this scope
   22 |                         if(j==w-1) cout<<c[i][j]<<endl;
      |                                          ^
a.cc:22:51: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   22 |                         if(j==w-1) cout<<c[i][j]<<endl;
      |                                                   ^~~~
      |                                                   std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:23:30: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   23 |                         else cout<<c[i][j]<<" ";
      |                              ^~~~
      |                              std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:23:36: error: 'c' was not declared in this scope
   23 |                         else cout<<c[i][j]<<" ";
      |                                    ^