Language: C++

#include <iostream>
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define lli long long int
using namespace std;
#define S second
#define F first
#define pb push_back 
#define M1 1000000007
#define M2 998244353
#define plli pair<lli,lli>
#define setit set<lli>::iterator seti
#define mapit map<lli,lli> ::iterator mapi
#define MP make_pair
#define MT make_tuple
#define PI 3.14159265358979323846
// map      iterator->first  iterator.first
// map      mp[key]=value
// set      *s.begin()
// vector   v[j]=value
// pair     p.first p.second
// vector of pairs v[j].first v[j].second
// tuple    get<index>(tuple_name)
// vector of tuples get<index>(v[j])  sort(v.begin(),v.end())
//priority queue .top() .pop() .push()
// __gcd(x,y)
#define mini(x,y) (y + ((x - y) & ((x - y) >>(sizeof(int) * CHAR_BIT - 1))))
#define maxi(x,y) (x - ((x - y) & ((x - y) >> (sizeof(int) * CHAR_BIT - 1))))
#define fr(j,a,b) for(j=a;j<b;j++)

int power(int x, unsigned int y, int p)  
{    int res = 1;    
     x = x % p;
     if (x == 0) return 0;
     while (y > 0)  
     {  if (y & 1)  
        res = (res*x) % p;  
        y = y>>1;
        x = (x*x) % p;  
     }  
    return res;  
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    lli t,i,j,n,x;
    x=0;
    string s,t;
        cin>>s>t;
        n=s.length();
        for(i=0;i<n;i++){
            if(s[j]!=t[j]){
                x++;
            }
        }
    cout<<x;
    
}



Compiler output:
a.cc: In function 'int main()':
a.cc:52:14: error: conflicting declaration 'std::string t'
   52 |     string s,t;
      |              ^
a.cc:50:9: note: previous declaration as 'long long int t'
   50 |     lli t,i,j,n,x;
      |         ^
a.cc:53:15: error: no match for 'operator>' (operand types are 'std::basic_istream<char>' and 'long long int')
   53 |         cin>>s>t;
      |         ~~~~~~^~
      |            |   |
      |            |   long long int
      |            std::basic_istream<char>
a.cc:53:15: note: candidate: 'operator>(int, long long int)' (built-in)
   53 |         cin>>s>t;
      |         ~~~~~~^~
a.cc:53:15: note:   no known conversion for argument 1 from 'std::basic_istream<char>' to 'int'
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181,
                 from a.cc:2:
/usr/include/c++/14/bits/regex.h:1176:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1176 |     operator>(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1176:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1236:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator>(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1236 |     operator>(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1236:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1329:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator>(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1329 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1329:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1403:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1403 |     operator>(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1403:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'long long int'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1497:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1497 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1497:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1573:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1573 |     operator>(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1573:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'long long int'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/regex.h:1673:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator>(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1673 |     operator>(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1673:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |         cin>>s>t;
      |                ^
In file included from /usr/include/c++/14/string:48,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:462:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  462 |     operator>(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:462:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:507:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  507 |     operator>(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:507:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1714 |     operator>(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1774 |     operator>(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   53 |         cin>>s>t;
      |                ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1058:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator>(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1058 |     operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1058:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'const std::pair<_T1, _T2>'
   53 |         cin>>s>t;
      |                ^
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:695:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  695 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:695:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/string_view:702:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  702 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:702:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/string_view:710:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  710 |     operator> (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:710:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'long long int'
   53 |         cin>>s>t;
      |                ^
/usr/include/c++/14/bits/basic_string.h:3915:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3915 |     operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3915:5: note:   template argument deduction/substitution failed:
a.cc:53:16: note:   'std::basic_istream