Language: C++

//vector<型> 配列名(要素数, 初期値);

//vector<int> data(3); // vectorによる配列
//int data[3]; // Cの配列
//array<int, 3> data; // arrayによる配列

//cout << vec.at(0) << endl;
//cout << vec[0] << endl; // .at(0)と同じ

//vec.pop_back(); // 末尾の要素を削除

//範囲for文
//for (配列の要素の型 変数名 : 配列変数) {
// 各要素に対する処理
//}


#include <bits/stdc++.h>
using namespace std;

int main()
{
  int H,W;
  cin>>H>>W;
  vector<char> a[100][101];
  vector<char> b[102][102];

  for (int i= 0; i < H; i++) {

    cin>>a[i];

    for(int i=0;i<H+2;i++){

      for (int j = 0; j < W+2; j++) {
        b[i][j]='#';
      }

    for(int i=0;i<H;i++){

      for(int j=0;j<W;j++){
        b[i+1][j+1]=a[i][j];
      }
    }

    for(int i=0;i<H+2;i++){

      for(int j=0;j<W+2;j++){
        cout<<b[i][j]<<endl;
      }
    }

  }

}


Compiler output:
a.cc: In function 'int main()':
a.cc:30:8: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'std::vector<char> [101]')
   30 |     cin>>a[i];
      |     ~~~^~~~~~
      |     |       |
      |     |       std::vector<char> [101]
      |     std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:18:
/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:30:13: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'std::vector<char>*'
   30 |     cin>>a[i];
      |          ~~~^
/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:30:13: error: invalid conversion from 'std::vector<char>*' to 'short int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(short int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'short unsigned int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(short unsigned int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'unsigned int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(unsigned int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'long int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(long int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'long unsigned int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(long unsigned int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'long long int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(long long int)((std::vector<char>*)(& a[i]))' 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:30:13: error: invalid conversion from 'std::vector<char>*' to 'long long unsigned int' [-fpermissive]
   30 |     cin>>a[i];
      |          ~~~^
      |             |
      |             std::vector<char>*
a.cc:30:13: error: cannot bind rvalue '(long long unsigned int)((std::vector<char>*)(& a[i]))' 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:30:13: error: cannot bind non-const lvalue reference of type 'void*&' to an rvalue of type 'void*'
   30 |     cin>>a[i];
      |          ~~~^
/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 'std::vector<char> [101]' 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 'std::vector<char> [101]' 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 'std::vector<char> [101]' 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 'std::vector<char> [101]' 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& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_i