Submission #90657

#	Time	Username	Problem	Language	Result	Execution time	Memory
90657		popovicirobert	Divide and conquer (IZhO14_divide)	C++14	0 / 100	122 ms	12944 KiB

divide

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define ld long double
// 217
// 44

using namespace std;

const int MAXN = (int) 1e5;

int x[MAXN + 1];
ll g[MAXN + 1], d[MAXN + 1];

bool cmp(const int &a, const int &b) {
    if(x[a] - d[a] == x[b] - d[b])
        return a < b;
    return x[a] - d[a] < x[b] - d[b];
}

map <ll, int> mp;

int aint[4 * MAXN + 1];

inline void refresh(int nod) {
    aint[nod] = min(aint[2 * nod], aint[2 * nod + 1]);
}

void update(int nod, int left, int right, int pos, int val) {
    if(left == right) {
        aint[nod] = min(val, aint[nod]);
    }
    else {
        int mid = (left + right) / 2;
        if(pos <= mid) update(2 * nod, left, mid, pos, val);
        else update(2 * nod + 1, mid + 1, right, pos, val);
        refresh(nod);
    }
}

int query(int nod, int left, int right, int l, int r) {
    if(l <= left && right <= r) {
        return aint[nod];
    }
    else {
        int mid = (left + right) / 2;
        int ans = 1e9;
        if(l <= mid) ans = min(ans, query(2 * nod, left, mid, l, r));
        if(mid < r) ans = min(ans, query(2 * nod + 1, mid + 1, right, l, r));
        refresh(nod);
        return ans;
    }
}

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, n;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n;
    vector <int> nrm(n + 1);
    iota(nrm.begin(), nrm.end(), 0);
    for(i = 1; i <= n; i++) {
        cin >> x[i] >> g[i] >> d[i];
        d[i] += d[i - 1];
        g[i] += g[i - 1];
    }
    sort(nrm.begin(), nrm.end(), cmp);
    nrm.resize(unique(nrm.begin(), nrm.end()) - nrm.begin());
    int cur = 0;
    for(auto it : nrm) {
        mp[x[it] - d[it]] = ++cur;
    }
    for(i = 1; i <= 4 * cur; i++) {
        aint[i] = n;
    }
    ll ans = 0;
    for(i = 1; i <= n; i++) {
        update(1, 1, cur, mp[x[i - 1] - d[i - 1]], i - 1);
        int pos = query(1, 1, cur, mp[x[i] - d[i]], cur);
        ans = max(ans, g[i] - g[pos]);
        if(1 <= d[i] - d[i - 1]) {
            ans = max(ans, g[i] - g[i - 1]);
        }
    }
    cout << ans;
    //cin.close();
    //cout.close();
    return 0;
}

• Subtask 1: 0 / 17
• Subtask 2: 0 / 31
• Subtask 3: 0 / 52