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OI-codes/S2OJ/1805/1805.cpp

85 lines
1.8 KiB
C++

#include <iostream>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 1e5 + 5;
const long long INF = 0x3f3f3f3f'3f3f3f3f;
struct node {
long long max;
node *lchild, *rchild;
node()
: max(-INF), lchild(nullptr), rchild(nullptr) {}
void pushup() {
max = -INF;
if (lchild) max = std::max(max, lchild->max);
if (rchild) max = std::max(max, rchild->max);
}
};
int k, m, d, a, n, t[N], b[N];
long long f[N];
node *root;
void modify(node *&cur, int l, int r, int x, long long v) {
if (!cur) cur = new node();
if (l == r) {
cur->max = v;
return;
}
int mid = l + r >> 1;
if (x <= mid) modify(cur->lchild, l, mid, x, v);
else modify(cur->rchild, mid + 1, r, x, v);
cur->pushup();
}
long long query(node *cur, int l, int r, int ql, int qr) {
if (!cur) return -INF;
if (ql <= l && r <= qr) return cur->max;
int mid = l + r >> 1;
long long res = -INF;
if (ql <= mid) res = std::max(res, query(cur->lchild, l, mid, ql, qr));
if (qr > mid) res = std::max(res, query(cur->rchild, mid + 1, r, ql, qr));
return res;
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> k >> m >> d >> a >> n;
for (int i = 1; i <= n; i++) {
cin >> t[i] >> b[i];
}
t[0] = k, t[n + 1] = m;
modify(root, 0, d - 1, t[0] % d, static_cast<long long>(t[0]) / d * a);
for (int i = 1; i <= n + 1; i++) {
f[i] = std::max(
query(root, 0, d - 1, 0, (t[i] - 1) % d),
query(root, 0, d - 1, (t[i] - 1) % d + 1, d - 1) + a)
- static_cast<long long>(t[i] - 1) / d * a - a + b[i];
modify(root, 0, d - 1, t[i] % d, f[i] + static_cast<long long>(t[i]) / d * a);
}
cout << f[n + 1] << endl;
return 0;
}