#include <bits/stdc++.h>
using namespace std;
#define int long long
#ifdef evenvalue
#include "debug.h"
#define debug(...) print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...)
#endif
using int64 = long long;
using ld = long double;
template<typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using max_heap = priority_queue<T, vector<T>, less<T>>;
namespace read {
int Int() {
int x;
cin >> x;
return x;
}
int64 Int64() {
int64 x;
cin >> x;
return x;
}
char Char() {
char c;
cin >> c;
return c;
}
string String() {
string s;
cin >> s;
return s;
}
double Double() {
return stod(String());
}
ld LongDouble() {
return stold(String());
}
template<typename T1, typename T2>
pair<T1, T2> Pair() {
pair<T1, T2> p;
cin >> p.first >> p.second;
return p;
}
template<typename T>
vector<T> Vec(const int n) {
vector<T> v(n);
for (T &x : v) {
cin >> x;
}
return v;
}
template<typename T>
vector<vector<T>> VecVec(const int n, const int m) {
vector<vector<T>> v(n);
for (vector<T> &vec : v) {
vec = Vec<T>(m);
}
return v;
}
}//namespace read
constexpr int kInf = 1e9 + 10;
constexpr int64 kInf64 = 1e15 + 10;
constexpr int kMod = 1e9 + 7;
constexpr int kMaxN = 2e5 + 10;
template<class Node>
class LazySegTree {
using Unite_t = std::function<Node(const Node &, const Node &)>;
using Apply_t = std::function<void(Node &, const Node &)>;
using Unlazy = std::function<void(Node &)>;
size_t n = 0;
std::vector<Node> t;
Unite_t unite;
Apply_t apply;
Unlazy activate;
void push(const size_t x, const size_t l, const size_t r) {
const size_t mid = (l + r) / 2;
const size_t y = 2 * (mid - l + 1) + x;
apply(t[x + 1], t[x]);
apply(t[y], t[x]);
activate(t[x]);
}
void update(const size_t x, const size_t l, const size_t r, const size_t ql, const size_t qr, const Node upd) {
if (ql <= l and r <= qr) {
apply(t[x], upd);
return;
}
push(x, l, r);
const size_t mid = (l + r) / 2;
const size_t y = 2 * (mid - l + 1) + x;
if (ql <= mid) {
update(x + 1, l, mid, ql, qr, upd);
}
if (mid < qr) {
update(y, mid + 1, r, ql, qr, upd);
}
t[x] = unite(t[x + 1], t[y]);
}
Node query(const size_t x, const size_t l, const size_t r, const size_t ql, const size_t qr) {
if (ql <= l and r <= qr) {
return t[x];
}
push(x, l, r);
const size_t mid = (l + r) / 2;
const size_t y = 2 * (mid - l + 1) + x;
if (qr <= mid) {
return query(x + 1, l, mid, ql, qr);
} else if (mid < ql) {
return query(y, mid + 1, r, ql, qr);
} else {
return unite(query(x + 1, l, mid, ql, qr), query(y, mid + 1, r, ql, qr));
}
}
void build(const int x, const int l, const int r, const std::vector<Node> &a) {
if (l == r) {
t[x] = a[l];
return;
}
const int mid = (l + r) / 2;
const int y = 2 * (mid - l + 1) + x;
build(x + 1, l, mid, a);
build(y, mid + 1, r, a);
t[x] = unite(t[x + 1], t[y]);
}
public:
LazySegTree(const size_t n, const Node e, const Unite_t unite, const Apply_t apply, const Unlazy activate)
: n(n), t(2 * n - 1, e), unite(unite), apply(apply), activate(activate) {}
LazySegTree(const std::vector<Node> &a, const Unite_t unite, const Apply_t apply, const Unlazy activate)
: n(a.size()), t(2 * n - 1), unite(unite), apply(apply), activate(activate) {
build(0, 0, n - 1, a);
}
void update(const int ql, const int qr, const Node upd) {
assert(0 <= ql and ql <= qr and qr < n);
update(0, 0, n - 1, ql, qr, upd);
}
Node query(const int ql, const int qr) {
assert(0 <= ql and ql <= qr and qr < n);
return query(0, 0, n - 1, ql, qr);
}
LazySegTree<Node> &operator=(LazySegTree<Node> other) {
swap(n, other.n);
swap(t, other.t);
swap(unite, other.unite);
swap(apply, other.apply);
swap(activate, other.activate);
return *this;
}
};
auto create_segtree(const int n) {
struct node {
int val = -kInf64;
int lazy = 0;
};
auto unite = [&](const node &l, const node &r) {
return node{max(l.val, r.val)};
};
auto apply = [&](node &x, const node y) {
x.val += y.lazy;
x.lazy += y.lazy;
};
auto activate = [&](node &x) {
x.lazy = 0;
};
LazySegTree<node> lst(n, node(), unite, apply, activate);
return lst;
}
enum direction {
left,
right
};
struct candidate {
int x;
int dist;
direction dir;
bool operator<(const candidate &other) const {
return dist < other.dist;
}
};
inline void solution() {
const int n = read::Int();
vector<int> a(n + 1);
for (int i = 1; i <= n; i++) {
a[i] = read::Int();
}
vector<int> left_ground(n + 1, -kInf);
if (a[1] == -1) left_ground[1] = 1;
for (int i = 2; i <= n; i++) {
left_ground[i] = (a[i] == -1 ? i : left_ground[i - 1]);
}
vector<int> right_ground(n + 1, kInf);
if (a[n] == -1) right_ground[n] = n;
for (int i = n - 1; i > 0; i--) {
right_ground[i] = (a[i] == -1 ? i : right_ground[i + 1]);
}
for (int i = 0; i < n; i++) {
if (a[i] == -1) break;
if (a[i] > 0) {
a[i]--;
break;
}
}
vector<int> walk(n + 1, -1);
for (int i = 1; i <= n; i++) {
if (a[i] != -1) continue;
if (right_ground[i] == kInf) continue;
walk[i] = 0;
}
vector<candidate> candidates;
for (int i = 1; i <= n; i++) {
if (a[i] <= 0) continue;
const int ld = i - left_ground[i];
const int rd = right_ground[i] - i;
if (ld <= rd) {
candidates.push_back({i, ld, direction::left});
} else {
candidates.push_back({i, rd, direction::right});
}
}
auto time = create_segtree(n + 2);
auto increase = [&](const int l, const int r, const int x) {
time.update(l, r, {0, x});
};
for (int i = 1; i <= n; i++) {
increase(i, i, 2 * (1 - i));
}
auto candy_walk = [&](const candidate c) -> bool {
const int t = -time.query(c.x, n).val;
if (t >= 2 * walk[left_ground[c.x]]) {
increase(c.x, n, 2 * walk[left_ground[c.x]]);
walk[left_ground[c.x]] = c.dist;
return true;
}
return false;
};
auto purchase = [&](const candidate c) -> int {
increase(c.x, c.x, kInf64);
int buy = 0;
if (c.dir == direction::left and right_ground[c.x] != kInf) {
buy += candy_walk(c);
}
int t = -time.query(c.x + 1, n + 1).val;
int me = -time.query(c.x, c.x).val;
int cycles = 0;
while (a[c.x] - buy > 0 and me >= c.dist and t >= 2 * c.dist) {
me -= 2 * c.dist;
t -= 2 * c.dist;
buy++;
cycles++;
}
increase(c.x + 1, n + 1, cycles * 2 * c.dist);
increase(c.x, c.x, cycles * 2 * c.dist - c.dist);
if (buy == 0) increase(c.x, c.x, -kInf64);
return buy;
};
sort(candidates.begin(), candidates.end());
int ans = 0;
for (const candidate c : candidates) {
ans -= purchase(c);
}
for (const int x : a) {
if (x == -1) continue;
ans += x;
}
cout << ans << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);
cout << fixed << setprecision(10);
int testcases = 1;
//cin >> testcases;
while (testcases--) {
solution();
}
}
Compilation message
In file included from /usr/include/c++/10/cassert:44,
from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
from tortoise.cpp:1:
tortoise.cpp: In instantiation of 'void LazySegTree<Node>::update(long long int, long long int, Node) [with Node = create_segtree(long long int)::node]':
tortoise.cpp:264:29: required from here
tortoise.cpp:153:40: warning: comparison of integer expressions of different signedness: 'const long long int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
153 | assert(0 <= ql and ql <= qr and qr < n);
| ~~~^~~
tortoise.cpp: In instantiation of 'Node LazySegTree<Node>::query(long long int, long long int) [with Node = create_segtree(long long int)::node]':
tortoise.cpp:272:37: required from here
tortoise.cpp:158:40: warning: comparison of integer expressions of different signedness: 'const long long int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
158 | assert(0 <= ql and ql <= qr and qr < n);
| ~~~^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
