Language: C++

//************************
//*  Date: 2018.9.8      *
//*  Problem:            *
//*  Author: xuziyuan    * 
//************************

#include <bits/stdc++.h>

#define rt0 return 0
#define rep(i,n) for(int i=0;i<n;i++)
#define repn(i,n) for(int i=1;i<=n;i++)
#define replet(c) for(char c='a';c<='z';c++)
#define LL long long
#define pii pair<int,int>
#define pb push_back
#define fi first
#define se second
#define mpr make_pair

using namespace std;

const LL MOD=1e9+7;

int n,m,x1=-1,y1=-1,x2=-1,y2=-1,ans=0;
int a[510][510];
vector <pii> pass;
vector <pair<pii,pii> > ans2;

int main()
{
	cin>>n>>m;
	rep(i,n)
	{
		rep(j,m)
		{
			scanf("%d",&a[i][j]);
			if(a[i][j]%2==1)
			{
				if(x1==-1)
				{
					x1=i;
					y1=j;
					continue;
				}
				x2=i;
				y2=j;
				pass.clear();
				for(int xx=x1;xx<=x2;xx++) pass.pb(pii(xx,y1));
				if(y1<=y2) for(int yy=y1+1;yy<=y2;yy++) pass.pb(pii(x2,yy));
				else for(int yy=y1-1;yy>=y2;yy--) pass.pb(pii(x2,yy));
				ans+=pass.size()-1;
				rep(k,pass.size()-1) ans2.pb({{pass[k].fi,pass[k].se},{pass[k+1].fi,pass[k+1].se}});
				x1=-1;
				y1=-1;
				x2=-1;
				y2=-1;
			}
		}	
	}
	printf("%d\n",ans);
	rep(i,ans) printf("%d %d %d %d\n",ans2[i].fi.fi+1,ans2[i].fi.se+1,ans2[i].se.fi+1,ans2[i].se.se+1);
	rt0;
}

Compiler output:
a.cc:24:15: error: 'int y1' redeclared as different kind of entity
   24 | int n,m,x1=-1,y1=-1,x2=-1,y2=-1,ans=0;
      |               ^~
In file included from /usr/include/features.h:523,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/c++config.h:683,
                 from /usr/include/c++/14/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:33,
                 from a.cc:7:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:257:1: note: previous declaration 'double y1(double)'
  257 | __MATHCALL (y1,, (_Mdouble_));
      | ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:42:43: error: assignment of function 'double y1(double)'
   42 |                                         y1=j;
      |                                         ~~^~
a.cc:48:77: error: no matching function for call to 'std::pair<int, int>::pair(int&, double (&)(double) noexcept)'
   48 |                                 for(int xx=x1;xx<=x2;xx++) pass.pb(pii(xx,y1));
      |                                                                             ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_pair.h:913:28: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(std::pair<_U1, _U2>&&) [with _U2 = _U1; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  913 |         explicit constexpr pair(pair<_U1, _U2>&& __p)
      |                            ^~~~
/usr/include/c++/14/bits/stl_pair.h:913:28: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:902:19: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(std::pair<_U1, _U2>&&) [with _U2 = _U1; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  902 |         constexpr pair(pair<_U1, _U2>&& __p)
      |                   ^~~~
/usr/include/c++/14/bits/stl_pair.h:902:19: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_pair.h:891:28: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_MoveConstructiblePair<_U1, _U2>() && (! _ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U2 = _U1; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<true, _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  891 |         explicit constexpr pair(_U1&& __x, _U2&& __y)
      |                            ^~~~
/usr/include/c++/14/bits/stl_pair.h:891:28: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:890:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  890 |                          bool>::type=false>
      |                                      ^~~~~
/usr/include/c++/14/bits/stl_pair.h:881:19: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_MoveConstructiblePair<_U1, _U2>() && _ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U2 = _U1; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<true, _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  881 |         constexpr pair(_U1&& __x, _U2&& __y)
      |                   ^~~~
/usr/include/c++/14/bits/stl_pair.h:881:19: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:880:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  880 |                          bool>::type=true>
      |                                      ^~~~
/usr/include/c++/14/bits/stl_pair.h:869:9: note: candidate: 'template<class _U2, typename std::enable_if<std::__and_<std::is_pointer<int>, std::__not_<std::is_reference<_Tp> >, std::is_constructible<int, _U1>, std::__not_<std::is_constructible<int, const _U1&> >, std::__not_<std::is_convertible<_U1, int> > >::value, bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(__zero_as_null_pointer_constant, _U2&&, ...) [with typename std::enable_if<std::__and_<std::is_pointer<_Tp>, std::__not_<std::is_reference<_U1> >, std::is_constructible<_T2, _U2>, std::__not_<std::is_constructible<_T1, const _U1&> >, std::__not_<std::is_convertible<_U2, _T2> > >::value, bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  869 |         pair(__zero_as_null_pointer_constant, _U2&& __y, ...)
      |         ^~~~
/usr/include/c++/14/bits/stl_pair.h:869:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:866:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  866 |                              bool> = false>
      |                                      ^~~~~
/usr/include/c++/14/bits/stl_pair.h:856:9: note: candidate: 'template<class _U2, typename std::enable_if<std::__and_<std::is_pointer<int>, std::__not_<std::is_reference<_Tp> >, std::is_constructible<int, _U1>, std::__not_<std::is_constructible<int, const _U1&> >, std::is_convertible<_U1, int> >::value, bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(__zero_as_null_pointer_constant, _U2&&, ...) [with typename std::enable_if<std::__and_<std::is_pointer<_Tp>, std::__not_<std::is_reference<_U1> >, std::is_constructible<_T2, _U2>, std::__not_<std::is_constructible<_T1, const _U1&> >, std::is_convertible<_U2, _T2> >::value, bool>::type <anonymous> = _U2; _T1 = int; _T2 = int]'
  856 |         pair(__zero_as_null_pointer_constant, _U2&& __y, ...)
      |         ^~~~
/usr/include/c++/14/bits/stl_pair.h:856:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:853:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  853 |                              bool> = true>
      |                                      ^~~~
/usr/include/c++/14/bits/stl_pair.h:843:9: note: candidate: 'template<class _U1, typename std::enable_if<std::__and_<std::__not_<std::is_reference<_Tp> >, std::is_pointer<int>, std::is_constructible<int, _U1>, std::__not_<std::is_constructible<int, const _U1&> >, std::__not_<std::is_convertible<_U1, int> > >::value, bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, __zero_as_null_pointer_constant, ...) [with typename std::enable_if<std::__and_<std::__not_<std::is_reference<_U1> >, std::is_pointer<_T2>, std::is_constructible<_T1, _U1>, std::__not_<std::is_constructible<_T1, const _U1&> >, std::__not_<std::is_convertible<_U1, _T1> > >::value, bool>::type <anonymous> = _U1; _T1 = int; _T2 = int]'
  843 |         pair(_U1&& __x, __zero_as_null_pointer_constant, ...)
      |         ^~~~
/usr/include/c++/14/bits/stl_pair.h:843:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:840:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  840 |                              bool> = false>
      |                                      ^~~~~
/usr/include/c++/14/bits/stl_pair.h:830:9: note: candidate: 'template<class _U1, typename std::enable_if<std::__and_<std::__not_<std::is_reference<_Tp> >, std::is_pointer<int>, std::is_constructible<int, _U1>, std::__not_<std::is_constructible<int, const _U1&> >, std::is_convertible<_U1, int> >::value, bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, __zero_as_null_pointer_constant, ...) [with typename std::enable_if<std::__and_<std::__not_<std::is_reference<_U1> >, std::is_pointer<_T2>, std::is_constructible<_T1, _U1>, std::__not_<std::is_constructible<_T1, const _U1&> >, std::is_convertible<_U1, _T1> >::value, bool>::type <anonymous> = _U1; _T1 = int; _T2 = int]'
  830 |         pair(_U1&& __x, __zero_as_null_pointer_constant, ...)
      |         ^~~~
/usr/include/c++/14/bits/stl_pair.h:830:9: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_pair.h:827:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  827 |                              bool> = true>
      |                                      ^~~~
/usr/include/c++/14/bits/stl_pair.h:789:28: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_ConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<int, _U2>::value)), int, int>::_ImplicitlyConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&) [with _U2 = _U1; typename std::enable