#include <bits/stdc++.h> using namespace std; #define ll long long int main() { int n; cin >> n; vector<int> a(n+1); int best = 2*n+1; for (int i=0; i<n; ++i) cin >> a[i+1]; vector<int> pos(n+1); vector<int> first_at_least(n+1); vector<int> last_at_least(n+1); for (int i=1; i<=n; ++i) pos[a[i]] = i; first_at_least[1] = 1; for (int i=2; i<=n; ++i) { int j=first_at_least[i-1]; while (a[j] < i) j++; first_at_least[i] = j; } last_at_least[1] = n; for (int i=2; i<=n; ++i) { int j=last_at_least[i-1]; while (a[j] < i) j--; last_at_least[i] = j; } ll cnt = 0; for (int i=1; i<=n; ++i) if (a[i] >= (n+1)/2) { int m=a[i]; int l = first_at_least[m]; int r = last_at_least[m]; int len = 2*(n-m)+1; int min_left = max (r - (len - 1), 1); int max_right = min (l + len - 1, n); int max_left = max_right - (len-1); cnt += max (max_left - min_left + 1, 0); if (a[i]-1 >= (n+1)/2) { l = first_at_least[a[i] - 1]; r = max(pos[a[i]-1], last_at_least[m]); len = 2 * (n - m) + 2; min_left = max(r - (len - 1), 1); max_right = min(l + len - 1, n); max_left = max_right - (len - 1); cnt += max(max_left - min_left + 1, 0); } } cout << best << " " << cnt << endl; return 0; }
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 | #include <bits/stdc++.h> using namespace std; #define ll long long int main() { int n; cin >> n; vector<int> a(n+1); int best = 2*n+1; for (int i=0; i<n; ++i) cin >> a[i+1]; vector<int> pos(n+1); vector<int> first_at_least(n+1); vector<int> last_at_least(n+1); for (int i=1; i<=n; ++i) pos[a[i]] = i; first_at_least[1] = 1; for (int i=2; i<=n; ++i) { int j=first_at_least[i-1]; while (a[j] < i) j++; first_at_least[i] = j; } last_at_least[1] = n; for (int i=2; i<=n; ++i) { int j=last_at_least[i-1]; while (a[j] < i) j--; last_at_least[i] = j; } ll cnt = 0; for (int i=1; i<=n; ++i) if (a[i] >= (n+1)/2) { int m=a[i]; int l = first_at_least[m]; int r = last_at_least[m]; int len = 2*(n-m)+1; int min_left = max (r - (len - 1), 1); int max_right = min (l + len - 1, n); int max_left = max_right - (len-1); cnt += max (max_left - min_left + 1, 0); if (a[i]-1 >= (n+1)/2) { l = first_at_least[a[i] - 1]; r = max(pos[a[i]-1], last_at_least[m]); len = 2 * (n - m) + 2; min_left = max(r - (len - 1), 1); max_right = min(l + len - 1, n); max_left = max_right - (len - 1); cnt += max(max_left - min_left + 1, 0); } } cout << best << " " << cnt << endl; return 0; } |