Submission #1099405

#TimeUsernameProblemLanguageResultExecution timeMemory
1099405Neco_arcMaking Friends on Joitter is Fun (JOI20_joitter2)C++17
100 / 100
636 ms81380 KiB
#include <bits/stdc++.h> #define ll long long #define ull unsigned long long #define all(x) x.begin(), x.end() #define Neco "Joitter" #define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin()) #define getbit(x,i) ((x >> i)&1) #define _left id * 2, l, mid #define _right id * 2 + 1, mid + 1, r #define cntbit(x) __builtin_popcountll(x) #define fi(i, a, b) for(int i = a; i <= b; i++) #define fid(i, a, b) for(int i = a; i >= b; i--) #define maxn (int) 2e5 + 7 using namespace std; const ll mod = 1e9 + 7; //972663749 const ll base = 911382323; mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); ll GetRandom(ll l, ll r) { return uniform_int_distribution<ll> (l, r)(rng); } int n, q; ll ans; int lab[maxn]; vector<pair<int, int>> Wait; set<int> In[maxn], Out[maxn], C[maxn]; int get_rt(int u) { return lab[u] < 0 ? u : lab[u] = get_rt(lab[u]); } int size(int u) { return C[u].size() + In[u].size() + Out[u].size(); } void Add(int u, int v) { u = get_rt(u), v = get_rt(v); In[v].insert(u), Out[u].insert(v); if(Out[v].count(u)) Wait.push_back({u, v}); } void uni(int u, int v) { u = get_rt(u), v = get_rt(v); if(u == v) return; if(size(u) < size(v)) swap(u, v); ans += 1ll * (-lab[u] * C[v].size()) + 1ll * (-lab[v] * C[u].size()); lab[u] += lab[v], lab[v] = u; for(int x : C[v]) { if(C[u].count(x)) ans -= -lab[u]; else C[u].insert(x); } for(int x : In[v]) { Out[x].erase(v), Add(x, u); } for(int x : Out[v]) { In[x].erase(v), Add(u, x); } In[v].clear(), Out[v].clear(), C[v].clear(); } void solve() { cin >> n >> q; fi(i, 1, n) lab[i] = -1, C[i] = {i}; fi(i, 1, q) { int u, v; cin >> u >> v; v = get_rt(v); if(get_rt(u) != v && !C[v].count(u)) { C[v].insert(u), ans += -lab[v]; u = get_rt(u); Add(u, v); while(!Wait.empty()) { int x, y; tie(x, y) = Wait.back(); Wait.pop_back(); uni(x, y); } } cout << ans << '\n'; } } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); if(fopen(Neco".inp", "r")) { freopen(Neco".inp", "r", stdin); freopen(Neco".out", "w", stdout); } int nTest = 1; // cin >> nTest; while(nTest--) { solve(); } return 0; }

Compilation message (stderr)

joitter2.cpp: In function 'int main()':
joitter2.cpp:98:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
joitter2.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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