#include <iostream> #include <vector> using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin >> n; vector<int>pos(n+1); for (int i = 0; i < n; i++) { int x; cin >> x; pos[x] = i; } int l = 1e9, r = 0; long long ans = 0; for (int i = 1; i <= n; i++) { l = min(l, pos[n-(i/2)]); r = max(r, pos[n-(i/2)]); ans += (long long)max(0, min(l, n-i) - max(0, r-i+1) + 1); } cout << 2*n+1 << ' ' << ans; }
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 | #include <iostream> #include <vector> using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin >> n; vector<int>pos(n+1); for (int i = 0; i < n; i++) { int x; cin >> x; pos[x] = i; } int l = 1e9, r = 0; long long ans = 0; for (int i = 1; i <= n; i++) { l = min(l, pos[n-(i/2)]); r = max(r, pos[n-(i/2)]); ans += (long long)max(0, min(l, n-i) - max(0, r-i+1) + 1); } cout << 2*n+1 << ' ' << ans; } |