#include <iostream> #include <algorithm> using namespace std; #define N 1000005 int n; int a[N]; int pos[N]; int expected; pair<int, int> range; long long ans; int main(){ cin.tie(0); ios_base::sync_with_stdio(0); cin >> n; for(int i=0;i<n;i++){ cin >> a[i]; pos[a[i]] = i; } expected = 2*n + 1; range = {pos[n], pos[n]}; for(int i=1;i<=n;i++){ if(i%2 == 0){ range.first = min(range.first, pos[n-i/2]); range.second = max(range.second, pos[n-i/2]); } ans += max(0, min(n-i, range.first) - max(0, range.second - i + 1) + 1); //cout << range.first << " " << range.second << " " << min(n-i, range.first) - max(0, range.second - i + 1) << " " << ans << "\n"; } cout << expected << " " << ans; return 0; } /* 5 1 4 3 5 2 */
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 | #include <iostream> #include <algorithm> using namespace std; #define N 1000005 int n; int a[N]; int pos[N]; int expected; pair<int, int> range; long long ans; int main(){ cin.tie(0); ios_base::sync_with_stdio(0); cin >> n; for(int i=0;i<n;i++){ cin >> a[i]; pos[a[i]] = i; } expected = 2*n + 1; range = {pos[n], pos[n]}; for(int i=1;i<=n;i++){ if(i%2 == 0){ range.first = min(range.first, pos[n-i/2]); range.second = max(range.second, pos[n-i/2]); } ans += max(0, min(n-i, range.first) - max(0, range.second - i + 1) + 1); //cout << range.first << " " << range.second << " " << min(n-i, range.first) - max(0, range.second - i + 1) << " " << ans << "\n"; } cout << expected << " " << ans; return 0; } /* 5 1 4 3 5 2 */ |