1D1D决策单调性dp
int a[200]; int n; struct node { int l, r, p; //node() {} //node(int a, int b, int c) :l(a), r(b), p(c) {} }q[2000]; double f[200], g[200]; double cal(int i, int j) { return a[j] + sqrt(i - j) - a[i]; } int find(node q, int x) { int l = q.l, r = q.r; while (l <= r) { int m = l + r >> 1; if (cal(m, q.p) > cal(m, x)) l = m + 1; else r = m - 1; } return l; } void Dp(double *f) { int head = 1, tail = 0; for (int i = 1; i <= n; ++i) { q[head].l++; if (head <= tail && q[head].l > q[head].r) ++head; if (head > tail || cal(n, q[tail].p) < cal(n, i)) { while (head <= tail && cal(q[tail].l, q[tail].p) < cal(q[tail].l, i)) --tail; if (head > tail) q[++tail] = node{ i, n, i }; else { int t = find(q[tail], i); q[tail].r = t - 1; q[++tail] = node{ t, n, i }; } } f[i] = cal(i, q[head].p); } } int main() { cin >> n; for (int i = 1; i <= n; ++i) cin >> a[i]; Dp(f); for (int i = 1; i <= n / 2; ++i) swap(a[i], a[n - i + 1]); Dp(g); for (int i = 1; i <= n; ++i) { printf("%d\n", max(0, (int)ceil(max(f[i], g[n - i + 1])))); } return 0; }