Submission #291971

#	Time	Username	Problem	Language	Result	Execution time	Memory
291971		khangal	Dreaming (IOI13_dreaming)	C++14	Compilation error	0 ms	0 KiB

dreaming

#include<bits/stdc++.h>
#include "dreaming.h" 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef int ll;
typedef double db;
typedef pair<ll,ll> pl;
typedef vector<ll> vl;
typedef vector<vl> vvl;
#define po pop_back
#define pb push_back
#define mk make_pair
#define mt make_tuple
#define lw lower_bound
#define up upper_bound
#define ff first
#define ss second
#define BOOST ios_base::sync_with_stdio(); cin.tie(0); cout.tie(0);
#define MOD 1000000007
#define MAX 1e18
#define MIN -1e18
#define rep(i,a,b) for(ll i=a;i<=b;i++)
#define per(i,a,b) for(ll i=b;i>=a;i--)
#define con continue
#define freopen freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define PI 3.14159265358979323846264338327950288419716939937510582097494459230781640628
#define read(x) scanf("%lld",&x);
#define print(x) printf("%lld ",x);
#define endl '\n';
typedef tree<ll , null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update> indexed_multi_set;
typedef tree<ll , null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
// template< typename T>
// using indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
int n,m,ans,mid,mn,mx,cnt,T,sum,h1,h2,e[1234567],b,c[1234567],d[1<<20],k,i,j,l,r,h,a,w,x,y,z,t;
bool used[1234567];
pair<int,int> p[1234567];
vector<pl> v[1234567],vec,vv1,vv2;
// string s1,s;
// int sz[1234567],par[1234567];
int tr[5234567],par[1234567];
ll dx[4]={-1,1,0,0},dy[4]={0,0,-1,1},c1[123][123];
map<ll,ll> mp;
pl dfs(int x , int p){
    used[x] = 1;
    pl res = {0, x};
    for(auto &u : v[x]) {
        if(u.ss == p) continue;
        pl pp = dfs(u.ss , x);
        res = max(res , pl(pp.ff + u.ff , pp.ss));
    }
    c[x] = res.ff;
    par[x] = p;
    return res;
}
int travelTime (int N, int M, int L, int A[], int B[], int T[]) {
    for ( int i = 0 ; i < M ; i ++ ) {
        v[ A [ i ] ] . push_back ( { T [ i ] , B [ i ] } ) ;
        v[ B [ i ] ] . push_back ( { T [ i ] , A [ i ] } ) ;
    }
    int maxx = 0;
    for ( int i = 0 ; i < N ; i ++ ) {
        if ( used [ i ] != 0 ) continue ;
        pl pr = dfs ( dfs ( i , -1 ) . second , -1 ) ;
        x = pr . second ;
        y = pr . first ;
        for ( int j = x ; j >= 0 ; j = par[ j ] ) {
            y = min ( y , max ( c [ j ] , pr . first - c [ j ] ) ) ;
        }
        vec . push_back ( y ) ; 
        maxx = max ( maxx , pr. first ) ; 
    }
    sort ( vec . rbegin ( ) , vec . rend ( ) ) ;
    if ( vec . size ( ) > 2 ) {
        ans = L + vec [ 0 ] + vec [ 1 ] ;
        for ( int i = 2 ; i < vec . size ( ) ; i ++ ) {
            ans = max ( ans , L + L + vec [ 1 ] + vec [ i ] ) ;
        }
    }
    else {
        if ( vec . size ( ) == 2 ) ans = L + vec [ 0 ] + vec [ 1 ] ;
        else ans = 0 ;
    }
    ans = max ( ans , maxx ) ;
    return ans ;
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:71:29: error: no matching function for call to 'std::vector<std::pair<int, int> >::push_back(int&)'
   71 |         vec . push_back ( y ) ;
      |                             ^
In file included from /usr/include/c++/9/vector:67,
                 from /usr/include/c++/9/queue:61,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:86,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/stl_vector.h:1184:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; std::vector<_Tp, _Alloc>::value_type = std::pair<int, int>]'
 1184 |       push_back(const value_type& __x)
      |       ^~~~~~~~~
/usr/include/c++/9/bits/stl_vector.h:1184:35: note:   no known conversion for argument 1 from 'int' to 'const value_type&' {aka 'const std::pair<int, int>&'}
 1184 |       push_back(const value_type& __x)
      |                 ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/stl_vector.h:1200:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; std::vector<_Tp, _Alloc>::value_type = std::pair<int, int>]'
 1200 |       push_back(value_type&& __x)
      |       ^~~~~~~~~
/usr/include/c++/9/bits/stl_vector.h:1200:30: note:   no known conversion for argument 1 from 'int' to 'std::vector<std::pair<int, int> >::value_type&&' {aka 'std::pair<int, int>&&'}
 1200 |       push_back(value_type&& __x)
      |                 ~~~~~~~~~~~~~^~~
dreaming.cpp:76:17: error: no match for 'operator+' (operand types are 'int' and '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'})
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/char_traits.h:39,
                 from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:423:5: note: candidate: 'template<class _Iterator> std::reverse_iterator<_Iterator> std::operator+(typename std::reverse_iterator<_Iterator>::difference_type, const std::reverse_iterator<_Iterator>&)'
  423 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:423:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/char_traits.h:39,
                 from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:1219:5: note: candidate: 'template<class _Iterator> std::move_iterator<_IteratorL> std::operator+(typename std::move_iterator<_IteratorL>::difference_type, const std::move_iterator<_IteratorL>&)'
 1219 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1219:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'} is not derived from 'const std::move_iterator<_IteratorL>'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6020:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 6020 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6020:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:56,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.tcc:1158:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 1158 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.tcc:1158:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const _CharT*' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:56,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.tcc:1174:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(_CharT, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 1174 |     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.tcc:1174:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6057:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)'
 6057 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6057:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6073:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, _CharT)'
 6073 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6073:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6085:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 6085 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6085:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6091:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&)'
 6091 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6091:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6097:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&)'
 6097 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6097:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6109:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&)'
 6109 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6109:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'const _CharT*' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6115:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(_CharT, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&)'
 6115 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6115:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6121:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, const _CharT*)'
 6121 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6121:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |                           ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from dreaming.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6127:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, _CharT)'
 6127 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6127:5: note:   template argument deduction/substitution failed:
dreaming.cpp:76:27: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
   76 |         ans = L + vec [ 0 ] + vec [ 1 ] ;
      |