#include <bits/stdc++.h> //Michał Kuśmirek using namespace std; //XIII LO Szczecin #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) #define REP(i, n) for(int i = 0; i < (n); ++i) using ll = long long; using pii = pair<int, int>; template<class T> int size(T && a) { return (int)(a.size()); } ostream& operator << (ostream &os, string str) { for(char c : str) os << c; return os; } template <class A, class B> ostream& operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.first << "," << p.second << ')'; } template <class T> auto operator << (ostream &os, T &&x) -> decltype(x.begin(), os) { os << '{'; for(auto it = x.begin(); it != x.end(); ++it) os << *it << (it == prev(x.end()) ? "" : " "); return os << '}'; } template <class T> ostream& operator << (ostream &os, vector<vector<T>> vec) { for(auto x : vec) os << "\n " << x; return os; } void dump() {} template <class T, class... Args> void dump(T &&x, Args... args) { cerr << x << "; "; dump(args...); } #ifdef DEBUG # define debug(x...) cerr << "[" #x "]: ", dump(x), cerr << '\n' #else # define debug(...) 0 #endif //-------------------------------------------------- int main() { ios_base::sync_with_stdio(0); cin.tie(0); int n; cin >> n; vector<int> a(n), position(n + 1); REP(i, n) { cin >> a[i]; position[a[i]] = i; } int l = position[n], r = position[n]; int mn = n; ll ans = 1; for(int x = n; x > 0; --x) { int p = position[x]; while(p < l) mn = min(mn, a[--l]); while(r < p) mn = min(mn, a[++r]); int len = 2 * (n - x + 1) - 2; if(len > n) break; REP(_, 2) { len += _; if(x == n) break; if(len < (r - l + 1)) continue; int st = max(0, r - len + 1), en = min(l, n - len); debug(l, r, len, st, en); debug(st, en); ans += en - st + 1; } debug(l, r, ans); } cout << 2 * n + 1 << ' ' << ans << '\n'; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 | #include <bits/stdc++.h> //Michał Kuśmirek using namespace std; //XIII LO Szczecin #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) #define REP(i, n) for(int i = 0; i < (n); ++i) using ll = long long; using pii = pair<int, int>; template<class T> int size(T && a) { return (int)(a.size()); } ostream& operator << (ostream &os, string str) { for(char c : str) os << c; return os; } template <class A, class B> ostream& operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.first << "," << p.second << ')'; } template <class T> auto operator << (ostream &os, T &&x) -> decltype(x.begin(), os) { os << '{'; for(auto it = x.begin(); it != x.end(); ++it) os << *it << (it == prev(x.end()) ? "" : " "); return os << '}'; } template <class T> ostream& operator << (ostream &os, vector<vector<T>> vec) { for(auto x : vec) os << "\n " << x; return os; } void dump() {} template <class T, class... Args> void dump(T &&x, Args... args) { cerr << x << "; "; dump(args...); } #ifdef DEBUG # define debug(x...) cerr << "[" #x "]: ", dump(x), cerr << '\n' #else # define debug(...) 0 #endif //-------------------------------------------------- int main() { ios_base::sync_with_stdio(0); cin.tie(0); int n; cin >> n; vector<int> a(n), position(n + 1); REP(i, n) { cin >> a[i]; position[a[i]] = i; } int l = position[n], r = position[n]; int mn = n; ll ans = 1; for(int x = n; x > 0; --x) { int p = position[x]; while(p < l) mn = min(mn, a[--l]); while(r < p) mn = min(mn, a[++r]); int len = 2 * (n - x + 1) - 2; if(len > n) break; REP(_, 2) { len += _; if(x == n) break; if(len < (r - l + 1)) continue; int st = max(0, r - len + 1), en = min(l, n - len); debug(l, r, len, st, en); debug(st, en); ans += en - st + 1; } debug(l, r, ans); } cout << 2 * n + 1 << ' ' << ans << '\n'; } |