#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 5; #define st first #define nd second typedef pair<int,int> pun; typedef long long ll; int main() { ios_base::sync_with_stdio(false); int n; cin >> n; vector<int> v; vector<int> where; where.resize(n+1); for (int i = 0; i < n; i ++) { int x; cin >> x; v.push_back(x); where[v[i]] = i; } int ile = n; int p = where[n]; int k = where[n]; ll res = 0; for (int i = 1; i <= n; i ++) { int med = 2 * n - i; int x = (i+2)/2; if (i % 2 == 0) { p = min(p, where[n - x + 1]); k = max(k, where[n - x + 1]); // cerr << "i=" << i << " " << "n-x+1=" << n - x + 1 << " where=" << where[n - x + 1] << "\n"; } // cerr <<"i=" << i << "\n"; // cerr << "p=" << p << " k=" << k << "\n"; if (k - p + 1 > i) continue; // cerr << "add=" << k - p + 1 << "\n"; // cerr << "to_res=" << min(min(p+1, n - k), i - (k - p + 1) + 1) << "\n"; res += min(min(n - i + 1, min(p+1, n - k)), i - (k - p + 1) + 1); } cout << 2 * n + 1 << " " << res; }
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 | #include <bits/stdc++.h> using namespace std; const int N = 1e6 + 5; #define st first #define nd second typedef pair<int,int> pun; typedef long long ll; int main() { ios_base::sync_with_stdio(false); int n; cin >> n; vector<int> v; vector<int> where; where.resize(n+1); for (int i = 0; i < n; i ++) { int x; cin >> x; v.push_back(x); where[v[i]] = i; } int ile = n; int p = where[n]; int k = where[n]; ll res = 0; for (int i = 1; i <= n; i ++) { int med = 2 * n - i; int x = (i+2)/2; if (i % 2 == 0) { p = min(p, where[n - x + 1]); k = max(k, where[n - x + 1]); // cerr << "i=" << i << " " << "n-x+1=" << n - x + 1 << " where=" << where[n - x + 1] << "\n"; } // cerr <<"i=" << i << "\n"; // cerr << "p=" << p << " k=" << k << "\n"; if (k - p + 1 > i) continue; // cerr << "add=" << k - p + 1 << "\n"; // cerr << "to_res=" << min(min(p+1, n - k), i - (k - p + 1) + 1) << "\n"; res += min(min(n - i + 1, min(p+1, n - k)), i - (k - p + 1) + 1); } cout << 2 * n + 1 << " " << res; } |