#include<bits/stdc++.h> #define pb push_back using namespace std; typedef long long lld; constexpr int MAX_N = 1000000; int t[MAX_N+9], poz[MAX_N+9]; int main() { int n; scanf("%d", &n); for(int i = 1; i <= n; ++i) { scanf("%d", &t[i]); poz[t[i]] = i; } int l = n; int r = 1; lld wyn = 0; for(int i = n; i >= 1; --i) { l = min(l, poz[i]); r = max(r, poz[i]); int ll = 0; int rr = 0; int spots = (n-i)*2+1 - (r - l + 1); if(poz[i-1] < l) { ll = l - poz[i-1] - 1; rr = n - r; } else if(r < poz[i-1]) { ll = l-1; rr = poz[i-1] - r - 1; } else { spots = -1; } ll = min(ll, spots); rr = min(rr, spots); if(ll > rr) { swap(ll, rr); } //lld old_wyn = wyn; for(int j = 0; j <= ll; ++j) { wyn += min(rr, spots-j)+1; } //printf("%d: %lld\n", i, wyn-old_wyn); } printf("%d %lld\n", n*2+1, wyn); } /* 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 49 50 51 52 53 54 55 56 | #include<bits/stdc++.h> #define pb push_back using namespace std; typedef long long lld; constexpr int MAX_N = 1000000; int t[MAX_N+9], poz[MAX_N+9]; int main() { int n; scanf("%d", &n); for(int i = 1; i <= n; ++i) { scanf("%d", &t[i]); poz[t[i]] = i; } int l = n; int r = 1; lld wyn = 0; for(int i = n; i >= 1; --i) { l = min(l, poz[i]); r = max(r, poz[i]); int ll = 0; int rr = 0; int spots = (n-i)*2+1 - (r - l + 1); if(poz[i-1] < l) { ll = l - poz[i-1] - 1; rr = n - r; } else if(r < poz[i-1]) { ll = l-1; rr = poz[i-1] - r - 1; } else { spots = -1; } ll = min(ll, spots); rr = min(rr, spots); if(ll > rr) { swap(ll, rr); } //lld old_wyn = wyn; for(int j = 0; j <= ll; ++j) { wyn += min(rr, spots-j)+1; } //printf("%d: %lld\n", i, wyn-old_wyn); } printf("%d %lld\n", n*2+1, wyn); } /* 5 1 4 3 5 2 //*/ |