Language: C++

#include <iostream>
#include <string>
#include <cstdio>
#include <vector>
#include <queue>
#include <list>
#include <cstdlib>
#include <algorithm>
#include <set>
#include <map>
#include <deque>
#include <cstring>
#include <cmath>
//#include<bits/stdc++.h>
using namespace std;

const int dx[]={1,0,-1,0};
const int dy[]={0,1,0,-1};

const int SIZE=2005;
int n,m,q,x1,x2,y1,y2;
bool a[SIZE][SIZE],visited[SIZE][SIZE];

int go(int x,int y){
	if(!(x>=x1 && x<=x2 && y>=y1 && y<=y2)) return 0;
	if(x<0 || x>=n || y<0 || y>=m) return 0;
	if(!a[x][y]) return 0;
	if(visited[x][y]) return 0;
	visited[x][y]=true;
	for(int i=0;i<4;i++){
		int ux=dx[i]+x,uy=dy[i]+y;
		go(ux,uy);
	}
	return 1;
}

int main(){
	cin>>n>>m>>q;
	for(int i=0;i<n;i++){
		string tmp;
		cin>>tmp;
		for(int j=0;j<m;j++){
			a[i][j]=tmp[j]-'0';
		}
	}
	for(int k=0;k<q;k++){
		int ans=0;
		cin>>x1>>y1>>x2>>y2;
		--x1;
		--x2;
		--y1;
		--y2;
		memset(visited,0,sizeof(visited));
		for(int i=0;i<n;i++){
			for(int j=0;j<m;j++){
				if(!visited[i][j]){
					ans+=go(i,j);
				}
			}
		}
		cout<<ans<<endl;
	}
}


Compiler output:
a.cc:21:17: error: 'int y1' redeclared as different kind of entity
   21 | int n,m,q,x1,x2,y1,y2;
      |                 ^~
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/bits/requires_hosted.h:31,
                 from /usr/include/c++/14/iostream:38,
                 from a.cc:1:
/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 go(int, int)':
a.cc:25:33: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   25 |         if(!(x>=x1 && x<=x2 && y>=y1 && y<=y2)) return 0;
      |                                ~^~~~
a.cc: In function 'int main()':
a.cc:48:24: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                 ~~~~~~~^~~~
      |                    |     |
      |                    |     double(double) noexcept
      |                    std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(short int)y1' to 'short int&'
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(short unsigned int)y1' to 'short unsigned int&'
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(int)y1' to 'int&'
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(unsigned int)y1' to 'unsigned int&'
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(long int)y1' to 'long int&'
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(long unsigned int)y1' to 'long unsigned int&'
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(long long int)y1' to 'long long int&'
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(long long unsigned int)y1' to 'long long unsigned int&'
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
a.cc:48:26: error: cannot bind rvalue '(void*)y1' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:48:26: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   48 |                 cin>>x1>>y1>>x2>>y2;
      |                          ^~
      |                          |
      |                          double (*)(double) noexcept
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istr