Language: C++

#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sstream>
#include <map>
#include <set>
#include <vector>
#include <cmath>
#include <queue>
#include <random>

using namespace std;

#define min(a,b) ((a)<(b) ? (a):(b))
#define max(a,b) ((a)>(b) ? (a):(b))

int gcd(int a, int b){
    while( b ){
        int m = a % b;
        a = b;
        b = m;
    }
    return a;
}

int lcm(int a, int  b){
    return (a*b)/gcd(a,b);
}

int isPrim(int a){
    if(a==1){
        return 0;
    }
    for(int i=2;i<=(a+1)/2;i++){
        if(a%i==0){
            return 0;
        }
    }
    return 1;
}

long long mod_pow(long long x, long long n, long long mod){
    //xのn乗を計算するのにn乗を2進表記にして計算
    //x^22 = x^16 + x^4 + x^2
    long long ret=1;
    while(n>0){
        if(n%2==1){
            ret=(ret*x)%mod;//答えに付加
        }
        x=(x*x)%mod;//2乗
        n=n/2;
    }
    return ret;
}

struct VV{
    int x;
    int y;
    int z;
};

class LessInt {
public:
    bool operator()(const VV& riLeft, const VV& riRight) const {
        if(riLeft.x == riRight.x){
            return riLeft.y > riRight.y;
        }
        return riLeft.x > riRight.x;
        
    }
};

class indInt {
public:
    bool operator()(const VV& riLeft, const VV& riRight) const {
        return riLeft.x < riRight.x;
        
    }
};

struct XX{
    long long a;
    long long b;
};

class xxIntu {
public:
    bool operator()(const XX& riLeft, const XX& riRight) const {
        //第1条件
        if(riLeft.a != riRight.a){
            return riLeft.a > riRight.a;//<:昇順(小さい順)、>:降順(大きい順)
        }
        //第2条件
        return riLeft.b > riRight.b;
    }
};
bool operator< (const XX &riLeft, const XX &riRight){
    return riLeft.a < riRight.a;
};
bool operator> (const XX &riLeft, const XX &riRight){
    return riLeft.a > riRight.a;
};


int main(int argc, const char * argv[])
{
    //std::ios::sync_with_stdio(false);
    //scanf("%s",S);
    //scanf("%d",&N);
    //getline(cin, target);
    //cin >> x >> y;
    //ここから
    
    long long N,L;
    cin >> N >> L;

    vector<XX> a;
    a.clear();
    
    for(long long i=0;i<N;i++){
        long long tmp;
        cin >> tmp;
        XX v;
        v.a=tmp;
        v.b=i;
        a.push_back(v);
    }
    int f=0;
    vector<long long> ans;
    ans.clear();
    
    while(f==0){
        f=1;
        long long i;
        for(i=0;i<N-1;i++){
            for(long long j=i+1;j<N;j++){
                if(a[i].a==0){
                    break;
                }
                if(a[i].a+a[j].a>=L && a[j].a!=0){
                    f=0;
                    a[i].a=a[i].a+a[j].a;
                    
                    //a[j].a=0;
                    a.erase(a.begin()+j);
                    ans.push_back(j);
                    break;
                }
                if(a[j].a!=0){
                    break;
                }
            }
        }
    }
    int tmp=0;
    for(int i=0;i<N;i++){
        if(a[i]!=0){
            tmp++;
        }
    }
    if(tmp==1){
        cout << "Possible" << endl;
        for(int i=0;i<ans.size();i++){
            cout << ans[ans.size()-1-i] << endl;
        }
        
    }else{
        cout << "Impossible" << endl;
    }
    
    
    
    //ここまで
    //cout << "ans" << endl;改行含む
    //printf("%.0f\n",ans);//小数点以下表示なし
    //printf("%.7f\n",p);
    //printf("%f\n",pow(2,ans.size()));
    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:160:16: error: no match for 'operator!=' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} and 'int')
  160 |         if(a[i]!=0){
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/postypes.h:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::fpos<_StateT>'
  160 |         if(a[i]!=0){
      |                  ^
In file included from /usr/include/c++/14/string:43,
                 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:
/usr/include/c++/14/bits/allocator.h:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::allocator<_CharT>'
  160 |         if(a[i]!=0){
      |                  ^
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::reverse_iterator<_Iterator>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::reverse_iterator<_Iterator>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::move_iterator<_IteratorL>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::move_iterator<_IteratorL>'
  160 |         if(a[i]!=0){
      |                  ^
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:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::pair<_T1, _T2>'
  160 |         if(a[i]!=0){
      |                  ^
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:651:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  651 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:651:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   'XX' is not derived from 'std::basic_string_view<_CharT, _Traits>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/string_view:658:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  658 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:658:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   'XX' is not derived from 'std::basic_string_view<_CharT, _Traits>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/string_view:666:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  666 |     operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:666:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3833:5: 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>&)'
 3833 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3833:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3847:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3847 |     operator!=(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3847:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   mismatched types 'const _CharT*' and 'XX'
  160 |         if(a[i]!=0){
      |                  ^
/usr/include/c++/14/bits/basic_string.h:3860:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3860 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3860:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
  160 |         if(a[i]!=0){
      |                  ^
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2613:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2613 |     operator!=(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2613:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::tuple<_UTypes ...>'
  160 |         if(a[i]!=0){
      |                  ^
In file included from /usr/include/c++/14/bits/locale_facets.h:48,
                 from /usr/include/c++/14/bits/basic_ios.h:37,
                 from /usr/include/c++/14/ios:46:
/usr/include/c++/14/bits/streambuf_iterator.h:242:5: note: candidate: 'template<class _CharT, class _Traits> bool std::operator!=(const istreambuf_iterator<_CharT, _Traits>&, const istreambuf_iterator<_CharT, _Traits>&)'
  242 |     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
      |     ^~~~~~~~
/usr/include/c++/14/bits/streambuf_iterator.h:242:5: note:   template argument deduction/substitution failed:
a.cc:160:18: note:   '__gnu_cxx::__alloc_traits<std::allocator<XX>, XX>::value_type' {aka 'XX'} is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
  160 |         if(a[i]!=0){
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from a.cc:8:
/usr/include/c++/14/bits/stl_map.h:1557:5: note: candidate: 'template<class _Key, cla