Submission #1173586

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173586		dzhoz0	Divide and conquer (IZhO14_divide)	C++20	100 / 100	33 ms	7904 KiB

divide

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define INF 1e18
#define f first
#define s second
#define pii pair<int, int>
#define vi vector<int>

const int MOD = 1'000'000'000 + 7;

void setIO(string name = "")
{
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
#ifdef LOCAL
    freopen("inp.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#else
    if (!name.empty())
    {
        freopen((name + ".INP").c_str(), "r", stdin);
        freopen((name + ".OUT").c_str(), "w", stdout);
    }
#endif
}
// START OF DEBUG
#define db(val) "["#val" = "<<(val)<<"] "
#define print_op(...) ostream& operator<<(ostream& out, const __VA_ARGS__& u)
// for printing std::pair
template<class U, class V> print_op(pair<U, V>) {
    return out << "(" << u.first << ", " << u.second << ")";
}
// for printing collection
template<class Con, class = decltype(begin(declval<Con>()))>
typename enable_if<!is_same<Con, string>::value, ostream&>::type
operator<<(ostream& out, const Con& con) { 
    out << "{";
    for (auto beg = con.begin(), it = beg; it != con.end(); ++it)
        out << (it == beg ? "" : ", ") << *it;
    return out << "}";
}
// for printing std::tuple
template<size_t i, class T> ostream& print_tuple_utils(ostream& out, const T& tup) {
    if constexpr(i == tuple_size<T>::value) return out << ")"; 
    else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); 
}
template<class ...U> print_op(tuple<U...>) {
    return print_tuple_utils<0, tuple<U...>>(out, u);
}
// END OF DEBUG
//
struct Compressor {
    vi v;
    int sz() { return (int)v.size(); }

    void add(int x) {
        v.push_back(x);
    }
    
    void init() {
        sort(v.begin(), v.end());
        v.erase(unique(v.begin(), v.end()), v.end());
    }

    int id(int key) {
        return lower_bound(v.begin(), v.end(), key) - v.begin() + 1;
    }
};

const int MAXN = 2e5;

struct Camp {
    int x = 0, g = 0, d = 0;
    int pd = 0, pg = 0;
} a[MAXN + 5];

int bit[MAXN + 5];
void upd(int pos, int val) {
    // cout << "update: " << pos << ' ' << val << '\n';
    while(pos <= MAXN) {
        bit[pos] = max(bit[pos], val);
        pos += pos & (-pos);
    }
}

int get(int pos) {
    int res = -INF;
    while(pos > 0) {
        res = max(res, bit[pos]);
        pos -= pos & (-pos);
    }
    return res;
}

void solve()
{
    int n; cin >> n;
    for(int i = 1; i <= MAXN; i++) bit[i] = -INF; 

    for(int i = 1; i <= n; i++) {
        cin >> a[i].x >> a[i].g >> a[i].d;
        a[i].pd = a[i - 1].pd + a[i].d;
        a[i].pg = a[i - 1].pg + a[i].g;
        // cout << a[i].x << ' ' << a[i].pd << ' ' << a[i].pg << '\n';
    }

    Compressor cmp;
    for(int i = 1; i <= n; i++) {
        cmp.add(a[i].pd - a[i].x);
        cmp.add(a[i].pd - a[i].d - a[i].x);
    }
    cmp.init();
    // cout << cmp.v << '\n';
    // solve
    int res = 0;
    for(int i = 1; i <= n; i++) {
        res = max(res, a[i].g);
        // for(int j = 1; j <= 20; j++) cout << bit[i] << ' '; cout << '\n';
        // cout << db(i) << ' ' << cmp.id(a[i].pd - a[i].x) << '\n';
        res = max(res, a[i].pg + get(cmp.id(a[i].pd - a[i].x)));
        // cout << res << '\n';
        upd(cmp.id(a[i].pd - a[i].d - a[i].x), -a[i].pg + a[i].g); 
    }
    cout << res << '\n';
}
signed main()
{
    setIO();
    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}

Compilation message (stderr)

divide.cpp: In function 'void setIO(std::string)':
divide.cpp:23:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen((name + ".INP").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
divide.cpp:24:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |         freopen((name + ".OUT").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52