#include <iostream>
#include <vector>
using namespace std;
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<int>V(n);
for(int &v : V)
cin >> v;
vector<int>Vinv(n+1);
for(int i=0;i<n;i++)
Vinv[V[i]] = i;
long long result = 0;
for(int i = 1, rl = Vinv[n], rr = Vinv[n], li = n; i <= n; i++) {
if (i % 2 == 0)
li--;
rl = min(rl, Vinv[li]);
rr = max(rr, Vinv[li]);
int left = rl, right = n-rr-1;
int base = rr-rl+1;
if (i < base)
continue;
int minr = max(i-base-left, 0);
int maxr = min(right, i-base);
result += maxr - minr + 1;
}
cout << 2*n+1 << " " << result << "\n";
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 | #include <iostream> #include <vector> using namespace std; int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vector<int>V(n); for(int &v : V) cin >> v; vector<int>Vinv(n+1); for(int i=0;i<n;i++) Vinv[V[i]] = i; long long result = 0; for(int i = 1, rl = Vinv[n], rr = Vinv[n], li = n; i <= n; i++) { if (i % 2 == 0) li--; rl = min(rl, Vinv[li]); rr = max(rr, Vinv[li]); int left = rl, right = n-rr-1; int base = rr-rl+1; if (i < base) continue; int minr = max(i-base-left, 0); int maxr = min(right, i-base); result += maxr - minr + 1; } cout << 2*n+1 << " " << result << "\n"; return 0; } |
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