제출 #986940

#제출 시각아이디문제언어결과실행 시간메모리
986940amine_arouaPort Facility (JOI17_port_facility)C++17
100 / 100
2306 ms189500 KiB
#include <bits/stdc++.h> #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") using namespace std; #define pb push_back #define nl '\n' #define fore(i, y) for(int i = 0; i < y; i++) #define forr(i, x, y) for(int i = x;i<=y;i++) #define forn(i, y, x) for(int i = y; i >= x; i--) const int MAXN = 2000010; const int MOD = 1e9 + 7; int ans = 1; int n; bool is_bipartite = 1; int idx[MAXN] , lt[MAXN] , rt[MAXN] , col[MAXN] , vis[MAXN]; vector<pair<int ,int>> vp[2]; const int INF = 2e6 + 10; struct segMin { int BASE; vector<int> tree; void init(int _n ) { BASE = _n; while(__builtin_popcount(BASE) != 1) { BASE++; } tree.assign(2*BASE , INF); } void upd(int x , int y) { tree[x + BASE] = y; for(int j = (x + BASE)/2 ; j >= 1; j/=2) { tree[j] = min(tree[2*j] , tree[2*j + 1]); } } int query(int l , int r) { if(l > r) return INF; l+=BASE; r+=BASE; if(l == r) return tree[l]; int left = tree[l] , right = tree[r]; while(l + 1 < r) { if(l % 2 == 0) left = min(left , tree[l + 1]); if(r % 2 == 1) right = min(tree[r - 1] , right); l>>=1; r>>=1; } return min(left , right); } }sL; struct segMax { int BASE; vector<int> tree; void init(int _n ) { BASE = _n; while(__builtin_popcount(BASE) != 1) { BASE++; } tree.assign(2*BASE , -INF); } void upd(int x , int y) { tree[x + BASE] = y; for(int j = (x + BASE)/2 ; j >= 1; j/=2) { tree[j] = max(tree[2*j] , tree[2*j + 1]); } } int query(int l , int r) { if(l > r) return -INF; l+=BASE; r+=BASE; if(l == r) return tree[l]; int left = tree[l] , right = tree[r]; while(l + 1 < r) { if(l % 2 == 0) left = max(left , tree[l + 1]); if(r % 2 == 1) right = max(tree[r - 1] , right); l>>=1; r>>=1; } return max(left , right); } }sR; void dfs(int x , int c) { if(vis[x]) { if(c != col[x]) is_bipartite = 0; return ; } vp[c].pb({lt[x] , rt[x]}); col[x] = c; vis[x] = 1; while(true) { int r = sR.query(lt[x] + 1 , rt[x] - 1); if(r <= rt[x]) break; int i = idx[r]; sR.upd(lt[i] , -INF); sL.upd(rt[i] , INF); dfs(i , 1 - c); } while(true) { int l = sL.query(lt[x] + 1 , rt[x] - 1); if(l >= lt[x]) break; int i = idx[l]; sR.upd(lt[i] , -INF); sL.upd(rt[i] , INF); dfs(i , 1 - c); } } bool check(int t) { sort(vp[t].begin() , vp[t].end()); set<int> s; for(auto [l , r] : vp[t]) { auto it = s.lower_bound(r); if(it != s.begin()) { it--; if(l < *it) return 0; } s.insert(r); } return 1; } signed main() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cin>>n; sL.init(2*n + 1); sR.init(2*n + 1); fore(i , n) { cin>>lt[i]>>rt[i]; sL.upd(rt[i] , lt[i]); sR.upd(lt[i] , rt[i]); idx[lt[i]] = i; idx[rt[i]] = i; } fore(i , n) { if(!vis[i]) { dfs(i , 0); ans = (ans * 2)%MOD; } } if(check(0) && check(1)) cout<<ans<<nl; else cout<<0<<nl; }
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