Language: C++

#include<iostream>
#include<vector>
#include<set>
#include<cstring>
#include<string>
#include<cstdio>
#include<cstdlib>
#include<queue>
using namespace std;

struct edge{ int to, cap, rev; };

int n,m,s,t;
int x[1000],y[1000];
int fl,v;
bool visitv[300],visite[1000];
vector<int> r;

vector<edge> G[300];
bool used[300];

void add_edge(int from,int to, int cap){
  G[from].push_back( (edge){to,cap,G[to].size()});
  G[to].push_back( (edge){from,0,G[form].size()-1});
}

int dfs(int v, int t, int f){
  if(v==t)return f;
  used[v] = true;
  for(int i=0;i<(int)G[v].size();i++){
    edge &e = G[v][i];
    if(!used[e.to] && e.cap>0){
      int d = dfs(e.to,t,min(f,e.cap));
      if(d>0){
	e.cap -= d;
	G[e.cap][e.rev].cap += d;
	return d;
      }
    }
  }
  return 0;
}

int max_flow(int s,int t){
  int flow = 0;
  for(;;){
    memset(used,0,sizeof(used));
    int f=dfs(s,t,INF);
    if(f==0)return flow;
    flow += f;
  }
}

int main(){
  cin >> m >> n;
  for(int i=0;i<m;i++){
    cin >> x >> y;
    add_edge(x,y,1);
  }
  cin >> s >> t;

  fl = max_flow(s,t);

  for(int i=0;i<n;i++)visitv[i] = false;
  for(int i=0;i<m;i++)visite[i] = false;

  queue<int> q;
  q.push(t);

Compiler output:
a.cc: In function 'void add_edge(int, int, int)':
a.cc:23:46: warning: narrowing conversion of 'G[to].std::vector<edge>::size()' from 'std::vector<edge>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
   23 |   G[from].push_back( (edge){to,cap,G[to].size()});
      |                                    ~~~~~~~~~~^~
a.cc:24:36: error: 'form' was not declared in this scope; did you mean 'from'?
   24 |   G[to].push_back( (edge){from,0,G[form].size()-1});
      |                                    ^~~~
      |                                    from
a.cc: In function 'int max_flow(int, int)':
a.cc:48:19: error: 'INF' was not declared in this scope
   48 |     int f=dfs(s,t,INF);
      |                   ^~~
a.cc: In function 'int main()':
a.cc:57:9: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'int [1000]')
   57 |     cin >> x >> y;
      |     ~~~ ^~ ~
      |     |      |
      |     |      int [1000]
      |     std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 from a.cc:1:
/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:57:12: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'int*'
   57 |     cin >> x >> y;
      |            ^
/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:57:12: error: invalid conversion from 'int*' to 'short int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(short int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'short unsigned int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(short unsigned int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'unsigned int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(unsigned int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'long int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(long int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'long unsigned int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(long unsigned int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'long long int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(long long int)((int*)(& x))' 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:57:12: error: invalid conversion from 'int*' to 'long long unsigned int' [-fpermissive]
   57 |     cin >> x >> y;
      |            ^
      |            |
      |            int*
a.cc:57:12: error: cannot bind rvalue '(long long unsigned int)((int*)(& x))' 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:57:12: error: cannot bind non-const lvalue reference of type 'void*&' to an rvalue of type 'void*'
   57 |     cin >> x >> y;
      |            ^
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:25: note:   no known conversion for argument 1 from 'int [1000]' to 'float&'
  219 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:26: note:   no known conversion for argument 1 from 'int [1000]' to 'double&'
  223 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:31: note:   no known conversion for argument 1 from 'int [1000]' to 'long double&'
  227 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/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>]'
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:36: note:   no known conversion for argument 1 from 'int [1000]' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'}
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type&