Language: C++

#include <iostream>
#include <vector>
 
int main(){
    u_int a;	// width
    u_int b;	// height
    while(std::cin >> a >> b){
        if(a == 0 && b == 0){
            break;
        }
		
		// initialization
        std::vector<std::vector<u_int>> path(a+1, std::vector<int>(b+1, 1));
        //for(u_int i = 0; i < a+1; ++i){
        //    path[i].resize(b+1, 1);
        //}
        
        // construction
        u_int n;
        std::cin >> n;
        for(u_int i = 0; i < n; ++i){
            u_int x, y;
            std::cin >> x >> y;
            path[x][y] = 0;
        }
        
        // out path
        for(u_int i = 0; i < a+1; ++i) path[i][0] = 0;
        for(u_int i = 0; i < b+1; ++i) path[0][i] = 0;
        
        
        for(u_int x = 1; x <= a; ++x){
            for(u_int y = 1; y <= b; ++y){
                if(path[x][y] != 0 && !(x == 1 && y == 1)){
                    path[x][y] = path[x-1][y] + path[x][y-1];
                }
            }
        }
         
        std::cout << path[a][b] << std::endl;
         
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:75: error: no matching function for call to 'std::vector<std::vector<unsigned int> >::vector(u_int, std::vector<int>)'
   13 |         std::vector<std::vector<u_int>> path(a+1, std::vector<int>(b+1, 1));
      |                                                                           ^
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_vector.h:707:9: note: candidate: 'template<class _InputIterator, class> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with <template-parameter-2-2> = _InputIterator; _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >]'
  707 |         vector(_InputIterator __first, _InputIterator __last,
      |         ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:707:9: note:   template argument deduction/substitution failed:
a.cc:13:75: note:   deduced conflicting types for parameter '_InputIterator' ('unsigned int' and 'std::vector<int>')
   13 |         std::vector<std::vector<u_int>> path(a+1, std::vector<int>(b+1, 1));
      |                                                                           ^
/usr/include/c++/14/bits/stl_vector.h:678:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::initializer_list<_Tp>, const allocator_type&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; allocator_type = std::allocator<std::vector<unsigned int> >]'
  678 |       vector(initializer_list<value_type> __l,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:43: note:   no known conversion for argument 1 from 'u_int' {aka 'unsigned int'} to 'std::initializer_list<std::vector<unsigned int> >'
  678 |       vector(initializer_list<value_type> __l,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:659:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<unsigned int> >]'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:659:23: note:   no known conversion for argument 1 from 'u_int' {aka 'unsigned int'} to 'std::vector<std::vector<unsigned int> >&&'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |              ~~~~~~~~~^~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::false_type) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; allocator_type = std::allocator<std::vector<unsigned int> >; std::false_type = std::false_type]'
  640 |       vector(vector&& __rv, const allocator_type& __m, false_type)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:635:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::true_type) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; allocator_type = std::allocator<std::vector<unsigned int> >; std::true_type = std::true_type]'
  635 |       vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:635:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:624:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<unsigned int> >]'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:624:28: note:   no known conversion for argument 1 from 'u_int' {aka 'unsigned int'} to 'const std::vector<std::vector<unsigned int> >&'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |              ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >]'
  620 |       vector(vector&&) noexcept = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:601:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >]'
  601 |       vector(const vector& __x)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:601:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:569:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const value_type&, const allocator_type&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; size_type = long unsigned int; value_type = std::vector<unsigned int>; allocator_type = std::allocator<std::vector<unsigned int> >]'
  569 |       vector(size_type __n, const value_type& __value,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:569:47: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<unsigned int> >::value_type&' {aka 'const std::vector<unsigned int>&'}
  569 |       vector(size_type __n, const value_type& __value,
      |                             ~~~~~~~~~~~~~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const allocator_type&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; size_type = long unsigned int; allocator_type = std::allocator<std::vector<unsigned int> >]'
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:51: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<unsigned int> >::allocator_type&' {aka 'const std::allocator<std::vector<unsigned int> >&'}
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |                             ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >; allocator_type = std::allocator<std::vector<unsigned int> >]'
  542 |       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:531:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = std::vector<unsigned int>; _Alloc = std::allocator<std::vector<unsigned int> >]'
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:531:7: note:   candidate expects 0 arguments, 2 provided