Submission #139767

#TimeUsernameProblemLanguageResultExecution timeMemory
139767BTheroAliens (IOI16_aliens)C++17
Compilation error
0 ms0 KiB
// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()

//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "aliens.h"

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()
#define debug(x) cerr << #x << " = " << x << '\n';

#define fi first
#define se second

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;   
typedef pair<int, int> pii;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int MAXN = (int)5e4 + 5;
const int INF = (int)1e9;
const ll LINF = (ll)1e15;

struct Line {
    ll k, b;
    
    Line() {
        k = b = 0ll;
    }
    
    Line(ll k, ll b) : k(k), b(b) {}
    
    ll get(ll x) {
        return k * x + b;
    }
};

double inter(Line a, Line b) {
    return (double)(a.b - b.b) / (double)(b.k - a.k);
}

struct CHT {
    Line H[MAXN];
    int sz;
    
    CHT() {
        sz = 0;
    }
    
    bool good(Line a, Line b, Line c) {
        return inter(a, b) < inter(b, c);
    }
    
    void addLine(Line l) {
        while (sz >= 2 && !good(H[sz - 2], H[sz - 1], l)) {
            --sz;
        }
        
        H[sz++] = l;
    }
    
    ll query(ll x) {
        ll ret = LINF;
        
        for (int i = 0; i < sz; ++i) {
            ret = min(ret, H[i].get(x));
        }
        
        return ret;
    }
};

pii arr[MAXN];

int n, m, k;

bool cmp(pii a, pii b) {
    if (a.fi == b.fi) {
        return a.se > b.se;
    }
    
    return a.fi < b.fi;
}

void resolveOverlaps() {
    sort(arr + 1, arr + n + 1, cmp);
    int lim = 0, nn = 0;
    
    for (int i = 1; i <= n; ++i) {
        if (arr[i].se > lim) {
            arr[++nn] = arr[i];
            lim = arr[i].se;
        }
    }
    
    n = nn;
}

ll f(int a, int b) {
    int len = max(0, b - a);
    return len * 1ll * len;
}

ll solve() {
    for (int i = 1; i <= n; ++i) {
        if (arr[i].fi > arr[i].se) {
            swap(arr[i].fi, arr[i].se);
        }
        
        ++arr[i].se;
    }
    
    resolveOverlaps();
    vector<vector<ll> > dp(k + 5, vector<ll>(n + 5, 0));
    
    for (int i = 0; i <= k; ++i) {
        fill(dp[i] + 1, dp[i] + n + 1, LINF);
    }
    
    CHT T;
    
    for (int lvl = 1; lvl <= k; ++lvl) {
        T.sz = 0;
        
        for (int i = 1; i <= n; ++i) {
            Line l(-2 * arr[i].fi, dp[lvl - 1][i - 1]);
            l.b += arr[i].fi * 1ll * arr[i].fi;
            l.b -= f(arr[i].fi, arr[i - 1].se);
            T.addLine(l);
            dp[lvl][i] = T.query(arr[i].se) + arr[i].se * 1ll * arr[i].se;
        }
    }
    
    return dp[k][n];
}

ll take_photos(int _n, int _m, int _k, vector<int> r, vector<int> c) {
    n = _n;
    m = _m;
    k = _k;
    
    for (int i = 1; i <= n; ++i) {
        arr[i] = mp(r[i - 1] + 1, c[i - 1] + 1);
    }

    return solve();
}

Compilation message (stderr)

aliens.cpp: In function 'll solve()':
aliens.cpp:125:20: error: no match for 'operator+' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' and 'int')
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
In file included from /usr/include/c++/7/bits/stl_algobase.h:67:0,
                 from /usr/include/c++/7/bits/specfun.h:45,
                 from /usr/include/c++/7/cmath:1914,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:41,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/stl_iterator.h:397:5: note: candidate: template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename std::reverse_iterator<_Iterator>::difference_type, const std::reverse_iterator<_Iterator>&)
     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
     ^~~~~~~~
/usr/include/c++/7/bits/stl_iterator.h:397:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/bits/stl_algobase.h:67:0,
                 from /usr/include/c++/7/bits/specfun.h:45,
                 from /usr/include/c++/7/cmath:1914,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:41,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/stl_iterator.h:1198:5: note: candidate: template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename std::move_iterator<_IteratorL>::difference_type, const std::move_iterator<_IteratorL>&)
     operator+(typename move_iterator<_Iterator>::difference_type __n,
     ^~~~~~~~
/usr/include/c++/7/bits/stl_iterator.h:1198:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5876:5: 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>&)
     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5876:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:53:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.tcc:1157:5: 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>&)
     operator+(const _CharT* __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.tcc:1157:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:53:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.tcc:1173:5: 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>&)
     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.tcc:1173:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5913:5: 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*)
     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5913:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5929:5: 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)
     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5929:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5941:5: 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>&)
     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5941:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5947:5: 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>&&)
     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5947:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5953:5: 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>&&)
     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5953:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5965:5: 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>&&)
     operator+(const _CharT* __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5965:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5971:5: 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>&&)
     operator+(_CharT __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5971:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5977:5: 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*)
     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5977:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/string:52:0,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/istream:38,
                 from /usr/include/c++/7/sstream:38,
                 from /usr/include/c++/7/complex:45,
                 from /usr/include/c++/7/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/bits/basic_string.h:5983:5: 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)
     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
     ^~~~~~~~
/usr/include/c++/7/bits/basic_string.h:5983:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/ccomplex:39:0,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/complex:326:5: note: candidate: template<class _Tp> std::complex<_Tp> std::operator+(const std::complex<_Tp>&, const std::complex<_Tp>&)
     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
     ^~~~~~~~
/usr/include/c++/7/complex:326:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::complex<_Tp>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/ccomplex:39:0,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/complex:335:5: note: candidate: template<class _Tp> std::complex<_Tp> std::operator+(const std::complex<_Tp>&, const _Tp&)
     operator+(const complex<_Tp>& __x, const _Tp& __y)
     ^~~~~~~~
/usr/include/c++/7/complex:335:5: note:   template argument deduction/substitution failed:
aliens.cpp:125:22: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> > >::value_type {aka std::vector<long long int>}' is not derived from 'const std::complex<_Tp>'
         fill(dp[i] + 1, dp[i] + n + 1, LINF);
                      ^
In file included from /usr/include/c++/7/ccomplex:39:0,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52,
                 from aliens.cpp:7:
/usr/include/c++/7/complex:344:5: note: candidate: template<class _Tp> std::complex<_Tp> std::operator+(const _Tp&, const std::complex<_Tp>&)
     operator+(const _Tp& __x, const complex<_Tp>& __y)
     ^~~~~~~~
/u