#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const long long MOD = 1e9 + 7;
struct Line
{
long long k, m;
};
long long f(const Line &l, long long x)
{
return (l.k * x + l.m) % MOD;
}
bool bad(const Line &l1, const Line &l2, const Line &l3)
{
return (long double)(l3.m - l1.m) * (l1.k - l2.k)
<= (long double)(l2.m - l1.m) * (l1.k - l3.k);
}
vector<Line> mergeHull(const vector<Line> &A, const vector<Line> &B)
{
vector<Line> res;
for (auto l1 : A)
{
for (auto l2 : B)
{
Line nl;
nl.k = (l2.k * l1.k) % MOD;
nl.m = (l2.k * l1.m + l2.m) % MOD;
while (res.size() >= 2 && bad(res[res.size()-2], res.back(), nl))
res.pop_back();
res.push_back(nl);
}
}
return res;
}
struct SegTree
{
int n;
vector<vector<Line>> tree;
SegTree(int n): n(n), tree(4*n) {}
vector<Line> make_node(long long a, long long b)
{
vector<Line> v;
// f(x) = max(x+a, x*b)
v.push_back({1, a});
v.push_back({b, 0});
return v;
}
void build(int v, int l, int r, vector<pair<int,int>> &arr)
{
if (r - l == 1) {
tree[v] = make_node(arr[l].first, arr[l].second);
return;
}
int m = (l + r) / 2;
build(v*2, l, m, arr);
build(v*2+1, m, r, arr);
tree[v] = mergeHull(tree[v*2], tree[v*2+1]);
}
vector<Line> query(int v, int l, int r, int ql, int qr)
{
if (qr <= l || r <= ql) return {};
if (ql <= l && r <= qr) return tree[v];
int m = (l + r) / 2;
auto left = query(v*2, l, m, ql, qr);
auto right = query(v*2+1, m, r, ql, qr);
if (left.empty()) return right;
if (right.empty()) return left;
return mergeHull(left, right);
}
long long eval(const vector<Line> &hull, long long x)
{
long long res = 0;
for (auto &l : hull)
res = max(res, f(l, x));
return res;
}
};
int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, q;
cin >> n >> q;
vector<pair<int,int>> a(n);
for (int i = 0; i < n; i++)
cin >> a[i].first >> a[i].second;
SegTree st(n);
st.build(1, 0, n, a);
while (q--)
{
long long x;
int l, r;
cin >> x >> l >> r;
auto hull = st.query(1, 0, n, l, r);
cout << st.eval(hull, x) << '\n';
}
}
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 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | #include <iostream> #include <vector> #include <algorithm> using namespace std; const long long MOD = 1e9 + 7; struct Line { long long k, m; }; long long f(const Line &l, long long x) { return (l.k * x + l.m) % MOD; } bool bad(const Line &l1, const Line &l2, const Line &l3) { return (long double)(l3.m - l1.m) * (l1.k - l2.k) <= (long double)(l2.m - l1.m) * (l1.k - l3.k); } vector<Line> mergeHull(const vector<Line> &A, const vector<Line> &B) { vector<Line> res; for (auto l1 : A) { for (auto l2 : B) { Line nl; nl.k = (l2.k * l1.k) % MOD; nl.m = (l2.k * l1.m + l2.m) % MOD; while (res.size() >= 2 && bad(res[res.size()-2], res.back(), nl)) res.pop_back(); res.push_back(nl); } } return res; } struct SegTree { int n; vector<vector<Line>> tree; SegTree(int n): n(n), tree(4*n) {} vector<Line> make_node(long long a, long long b) { vector<Line> v; // f(x) = max(x+a, x*b) v.push_back({1, a}); v.push_back({b, 0}); return v; } void build(int v, int l, int r, vector<pair<int,int>> &arr) { if (r - l == 1) { tree[v] = make_node(arr[l].first, arr[l].second); return; } int m = (l + r) / 2; build(v*2, l, m, arr); build(v*2+1, m, r, arr); tree[v] = mergeHull(tree[v*2], tree[v*2+1]); } vector<Line> query(int v, int l, int r, int ql, int qr) { if (qr <= l || r <= ql) return {}; if (ql <= l && r <= qr) return tree[v]; int m = (l + r) / 2; auto left = query(v*2, l, m, ql, qr); auto right = query(v*2+1, m, r, ql, qr); if (left.empty()) return right; if (right.empty()) return left; return mergeHull(left, right); } long long eval(const vector<Line> &hull, long long x) { long long res = 0; for (auto &l : hull) res = max(res, f(l, x)); return res; } }; int main() { ios::sync_with_stdio(false); cin.tie(NULL); int n, q; cin >> n >> q; vector<pair<int,int>> a(n); for (int i = 0; i < n; i++) cin >> a[i].first >> a[i].second; SegTree st(n); st.build(1, 0, n, a); while (q--) { long long x; int l, r; cin >> x >> l >> r; auto hull = st.query(1, 0, n, l, r); cout << st.eval(hull, x) << '\n'; } } |
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