30 lines
898 B
C++
30 lines
898 B
C++
struct Line {
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mutable ll k, m, p;
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bool operator<(const Line& o) const { return k < o.k; }
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bool operator<(ll x) const { return p < x; }
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};
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struct LineContainer : multiset<Line, less<>> {
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// (for doubles, use inf = 1/.0, div(a,b) = a/b)
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static const ll inf = LLONG_MAX;
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ll div(ll a, ll b) { // floored division
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return a / b - ((a ^ b) < 0 && a % b); }
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bool isect(iterator x, iterator y) {
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if (y == end()) return x->p = inf, 0;
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if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
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else x->p = div(y->m - x->m, x->k - y->k);
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return x->p >= y->p;
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}
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void add(ll k, ll m) {
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auto z = insert({k, m, 0}), y = z++, x = y;
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while (isect(y, z)) z = erase(z);
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if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
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while ((y = x) != begin() && (--x)->p >= y->p)
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isect(x, erase(y));
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}
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ll query(ll x) {
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assert(!empty());
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auto l = *lower_bound(x);
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return l.k * x + l.m;
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}
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}; |