#include <bits/stdc++.h> #include <ext/pb_ds/tree_policy.hpp> #include <ext/pb_ds/assoc_container.hpp> using namespace std; using namespace __gnu_pbds; #if defined(__GNUC__) || defined(__clang__) #pragma GCC optimize("Ofast,unroll-loops,inline-functions,no-stack-protector") #pragma GCC target("avx2,fma,tune=native") #pragma clang loop vectorize(enable) #pragma clang loop interleave(enable) #endif #define int long long #define sz(x) (int)x.size() #define F first #define S second #define pb push_back #define nl '\n' #define o_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); typedef pair<int, int> pii; void file( string s = "" ) { if( s.empty() ) return; freopen((s + ".in").c_str(), "r", stdin); freopen((s + ".out").c_str(), "w", stdout); } const int N = 2e5 + 2; const int N1 = 1e6 + 2; const int inf = 1e9 + 2; const int INF = 1e18 + 2; const int mod = 1e9 + 7; int T = 1; void solve() { int n; cin >>n; set< pii > st; for( int i = 1, l, w; i <= n; ++i ) { cin >>l >>w; if( i == 1 ) { st.insert({l, w}); continue; } set< pii > _st; for( auto [l1, w1]: st ) { if( l == l1 ) _st.insert({min(l, w + w1), max(l, w + w1)}); if( w == w1 ) _st.insert({min(l + l1, w), max(l + l1, w)}); if( l == w1 ) _st.insert({min(l, l1 + w), max(l, l1 + w)}); if( w == l1 ) _st.insert({min(w, l + w1), max(w, l + w1)}); } st.swap(_st); } set< int > ans; for( auto [l, w]: st ) ans.insert(min(l, w)); cout <<sz(ans) <<nl; for( int l: ans ) cout <<l <<nl; } signed main() { file(""); ios_base::sync_with_stdio(false); cin.tie(nullptr); // cin >>T; while( T-- ) solve(); }

Main.cpp: In function 'void file(std::string)':
Main.cpp:29:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:30:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~