#include<bits/stdc++.h> using namespace std; using LL=long long; #define FOR(i,l,r) for(int i=(l);i<=(r);++i) #define REP(i,n) FOR(i,0,(n)-1) #define ssize(x) int(x.size()) template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';} template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';} #ifdef DEBUG #define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<'\n';}(x) #else #define debug(...) {} #endif int main() { cin.tie(0)->sync_with_stdio(0); int n; cin >> n; vector<int> wys(n); REP(i,n) { int x; cin >> x; wys[x - 1] = i; } int l = n; int r = -1; LL ans = 0; for (int i = n - 1; i >= 0; --i) { l = min(l, wys[i]); r = max(r, wys[i]); int d = 2 * (n - i) - 1 - (r - l + 1); if (d >= 0) { int mi = 0; int ma = d; mi = max(mi, d - (n - r - 1)); ma = min(ma, l); ans += max(0, ma - mi + 1); } if (i == n - 1) continue; --d; if (d >= 0) { int mi = 0; int ma = d; mi = max(mi, d - (n - r - 1)); ma = min(ma, l); ans += max(0, ma - mi + 1); } } 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 | #include<bits/stdc++.h> using namespace std; using LL=long long; #define FOR(i,l,r) for(int i=(l);i<=(r);++i) #define REP(i,n) FOR(i,0,(n)-1) #define ssize(x) int(x.size()) template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';} template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';} #ifdef DEBUG #define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<'\n';}(x) #else #define debug(...) {} #endif int main() { cin.tie(0)->sync_with_stdio(0); int n; cin >> n; vector<int> wys(n); REP(i,n) { int x; cin >> x; wys[x - 1] = i; } int l = n; int r = -1; LL ans = 0; for (int i = n - 1; i >= 0; --i) { l = min(l, wys[i]); r = max(r, wys[i]); int d = 2 * (n - i) - 1 - (r - l + 1); if (d >= 0) { int mi = 0; int ma = d; mi = max(mi, d - (n - r - 1)); ma = min(ma, l); ans += max(0, ma - mi + 1); } if (i == n - 1) continue; --d; if (d >= 0) { int mi = 0; int ma = d; mi = max(mi, d - (n - r - 1)); ma = min(ma, l); ans += max(0, ma - mi + 1); } } cout << 2 * n + 1 << ' ' << ans << '\n'; } |