#include<bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize("trapv") #define st first #define nd second #define pb(x) push_back(x) #define pp(x) pop_back(x) #define mp(a, b) make_pair(a, b) #define all(x) (x).begin(), (x).end() #define rev(x) reverse(all(x)) #define sor(x) sort(all(x)) #define sz(x) (int)(x).size() #define rsz(x) resize(x) using namespace std; ///~~~~~~~~~~~~~~~~~~~~~~~~~~ void debug(){cerr<<"\n";} template <typename H, typename... T> void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);} #define deb(x...) cerr<<#x<<" = ";debug(x); ///~~~~~~~~~~~~~~~~~~~~~~~~~ typedef long long ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<pii > vii; typedef vector<ll> vl; typedef vector<pll> vll; typedef string str; #define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL); mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const int N=2e5+5, INF=1e9+5, mod=1e9+7; int main(){ BOOST; int n; cin>>n; int l=n-1, r=0; vi gdzie(n); for(int i=0; i<n; i++){ int x; cin>>x; gdzie[x-1]=i; } ll ans=0; int ile=0; for(int i=1; i<=n; i++){ if(ile*2<=i){ ile++; l=min(l, gdzie[n-ile]); r=max(r, gdzie[n-ile]); } int dl=r-l+1; if(dl<=i){ ans+=min(l, n-i)-max(-1, r-i); //deb(l, r, dl, min(l, n-i), max(-1, r-i)); } } 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 | #include<bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize("trapv") #define st first #define nd second #define pb(x) push_back(x) #define pp(x) pop_back(x) #define mp(a, b) make_pair(a, b) #define all(x) (x).begin(), (x).end() #define rev(x) reverse(all(x)) #define sor(x) sort(all(x)) #define sz(x) (int)(x).size() #define rsz(x) resize(x) using namespace std; ///~~~~~~~~~~~~~~~~~~~~~~~~~~ void debug(){cerr<<"\n";} template <typename H, typename... T> void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);} #define deb(x...) cerr<<#x<<" = ";debug(x); ///~~~~~~~~~~~~~~~~~~~~~~~~~ typedef long long ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<pii > vii; typedef vector<ll> vl; typedef vector<pll> vll; typedef string str; #define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL); mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const int N=2e5+5, INF=1e9+5, mod=1e9+7; int main(){ BOOST; int n; cin>>n; int l=n-1, r=0; vi gdzie(n); for(int i=0; i<n; i++){ int x; cin>>x; gdzie[x-1]=i; } ll ans=0; int ile=0; for(int i=1; i<=n; i++){ if(ile*2<=i){ ile++; l=min(l, gdzie[n-ile]); r=max(r, gdzie[n-ile]); } int dl=r-l+1; if(dl<=i){ ans+=min(l, n-i)-max(-1, r-i); //deb(l, r, dl, min(l, n-i), max(-1, r-i)); } } cout<<2*n+1<<" "<<ans<<"\n"; } |