src.cpp:4:9: error: conflicting declaration 'int a'
int n,m,a,b;
^
src.cpp:3:14: note: previous declaration as 'std::vector<int> a [1000000]'
vector <int> a[1000000];
^
src.cpp: In function 'void docdulieu()':
src.cpp:8:18: error: cannot bind 'std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}' lvalue to 'std::basic_istream<char>&&'
cin >> n >> m >> a >> b;
^
In file included from C:/Debug/compiler/gcc/lib/gcc/mingw32/4.9.2/include/c++/sstream:38:0,
from C:/Debug/compiler/gcc/lib/gcc/mingw32/4.9.2/include/c++/complex:45,
from C:/Debug/compiler/gcc/lib/gcc/mingw32/4.9.2/include/c++/ccomplex:38,
from C:/Debug/compiler/gcc/lib/gcc/mingw32/4.9.2/include/c++/mingw32/bits/stdc++.h:52,
from src.cpp:1:
C:/Debug/compiler/gcc/lib/gcc/mingw32/4.9.2/include/c++/istream:872:5: note: initializing argument 1 of 'std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&) [with _CharT = char; _Traits = std::char_traits<char>; _Tp = std::vector<int> [1000000]]'
operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
^
src.cpp: In function 'int main()':
src.cpp:43:10: error: invalid conversion from 'std::vector<int>*' to 'int' [-fpermissive]
BFS(a)
^
src.cpp:18:6: note: initializing argument 1 of 'void BFS(int)'
void BFS (int x)
^
src.cpp:44:5: error: expected ';' before 'for'
for (int k = 1; k <=n; k++)
^
src.cpp:44:21: error: 'k' was not declared in this scope
for (int k = 1; k <=n; k++)
^