Submission #917643

#	Time	Username	Problem	Language	Result	Execution time	Memory
917643		Whisper	Divide and conquer (IZhO14_divide)	C++17	100 / 100	44 ms	12232 KiB

divide

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;

#define int long long
#define Base 41
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
struct Data{
    int x, g, d;
    friend istream& operator >> (istream& cin, Data& a){
        cin >> a.x >> a.g >> a.d;
        return cin;
    }
    friend ostream& operator << (ostream& cout, Data a){
        cout << a.x << " " << a.g << " " << a.d;
        return cout;
    }
};
int N;

int G[MAX], D[MAX];
int dp[MAX];
Data a[MAX];

struct FenwickTree{
    vector<int> f;
    int n;
    FenwickTree(int _n){
        this -> n = _n;
        f.resize(n + 5, LINF);
    }
    void modify(int p, int val){
        for (; p <= n; p += p & (-p)) minimize(f[p], val);
    }
    int query(int p){
        int res = LINF;
        for ( ; p > 0; p -= p & (-p)) minimize(res, f[p]);
        return res;;
    }
};
void Whisper(){
    cin >> N;
    for (int i = 1; i <= N; ++i) cin >> a[i];
    for (int i = 1; i <= N; ++i){
        G[i] = G[i - 1] + a[i].g;
        D[i] = D[i - 1] + a[i].d;
    }

    vector<int> comp;
    #define Find(x) lower_bound(all(comp), x) - comp.begin() + 1
    comp.push_back(D[0] - a[1].x);
    for (int i = 1; i <= N; ++i){
        comp.push_back(D[i] - a[i].x);
        comp.push_back(D[i] - a[i + 1].x);
    }
    sort(all(comp)); comp.resize(unique(all(comp)) - comp.begin());
    FenwickTree fen(sz(comp));

    fen.modify(Find(D[0] - a[1].x), 0);
    int ans = 0;
    for (int i = 1; i <= N; ++i){
        int id = Find(D[i] - a[i].x);
        int x = fen.query(id);
        maximize(ans, G[i] - x);
        fen.modify(Find(D[i] - a[i + 1].x), G[i]);
    }

    cout << ans;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

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