/* -*- coding: utf-8 -*- * * 1031.cc: No.1031 いたずら好きなお姉ちゃん - yukicoder */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; /* constant */ const int MAX_N = 100000; const int MAX_E2 = 1 << 18; // = 262144 const int INF = 1 << 30; /* typedef */ typedef long long ll; typedef pair pii; typedef queue qpii; template struct SegTreeMin { int n, e2; T nodes[MAX_E2], inf; SegTreeMin() {} void init(int n, T _inf) { inf = _inf; for (e2 = 1; e2 < n; e2 <<= 1); fill(nodes, nodes + MAX_E2, inf); } T &get(int i) { return nodes[e2 - 1 + i]; } void set(int i, T v) { get(i) = v; } void setall() { for (int j = e2 - 2; j >= 0; j--) nodes[j] = min(nodes[j * 2 + 1], nodes[j * 2 + 2]); } T min_range(int r0, int r1, int k, int i0, int i1) { if (r1 <= i0 || i1 <= r0) return inf; if (r0 <= i0 && i1 <= r1) return nodes[k]; int im = (i0 + i1) / 2; T v0 = min_range(r0, r1, k * 2 + 1, i0, im); T v1 = min_range(r0, r1, k * 2 + 2, im, i1); return min(v0, v1); } T min_range(int r0, int r1) { return min_range(r0, r1, 0, 0, e2); } }; /* global variables */ int ps[MAX_N]; SegTreeMin st; /* subroutines */ /* main */ int main() { int n; scanf("%d", &n); st.init(n, pii(INF, -1)); for (int i = 0; i < n; i++) { scanf("%d", ps + i); st.set(i, pii(ps[i], i)); } st.setall(); ll sum = 0; qpii q; q.push(pii(0, n)); while (! q.empty()) { pii u = q.front(); q.pop(); int ul = u.first, ur = u.second; pii minp = st.min_range(ul, ur); int mini = minp.second; int lc = 0; for (int i = mini - 1, pp = 0; i >= ul; i--) if (pp < ps[i]) lc++, pp = ps[i]; int rc = 0; for (int i = mini + 1, pp = 0; i < ur; i++) if (pp < ps[i]) rc++, pp = ps[i]; //printf("min[%d,%d]=%d,%d, %d,%d\n", ul, ur, minp.first, mini, lc, rc); sum += lc + rc; if (mini > ul) q.push(pii(ul, mini)); if (mini + 1 < ur) q.push(pii(mini + 1, ur)); } printf("%lld\n", sum); return 0; }