2021.3.8

\(\mathcal{A}\)

for (int j = 2; j <= m; ++j) {
	for (int i = 1; i <= n; ++i)
		g[i] = f[i];
	int top = 0, k = 0;
	for (int i = j - 1; i <= n; ++i) {
		while (k < top && s[k + 1].y - s[k].y <= a[i] * (s[k + 1].x - s[k].x)) ++k;
		f[i] = a[i] * s[k].x - s[k].y;
		Vec u = Vec(a[i], a[i] * a[i] - g[i]);
		while (top > k && cross(u - s[top - 1], s[top] - s[top - 1]) >= 0) --top;
		s[++top] = u;
	}
}

下面的慢很多

for (int j = 2; j <= m; ++j) {
	int top = 0, k = 0;
	for (int i = j - 1; i <= n; ++i) {
		while (k < top && s[k + 1].y - s[k].y <= a[i] * (s[k + 1].x - s[k].x)) ++k;
		dp[i][j] = a[i] * s[k].x - s[k].y;
		Vec u = Vec(a[i], a[i] * a[i] - dp[i][j - 1]);
		while (top > k && cross(u - s[top - 1], s[top] - s[top - 1]) >= 0) --top;
		s[++top] = u;
	}
}

\(\mathcal{B}\)

typedef long long ll
ll x = 1e18 + 1
ll y = (ll)1e18 + 1

x还是1000000000000000000，y是1000000000000000001