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Submission #918046

# Submission time Handle Problem Language Result Execution time Memory
918046 2024-01-29T12:49:41 Z borisAngelov Divide and conquer (IZhO14_divide) C++17
48 / 100
 1000 ms 8360 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 100005;
const long long inf = (1LL << 62);

int n;

struct Element
{
    int pos;
    int gold;
    int energy;
};

Element a[maxn];

long long prefEenrgy[maxn];
long long prefGold[maxn];

struct SegmentTree
{
    long long tree[4 * maxn];
    long long lazy[4 * maxn];

    void build(int node, int l, int r)
    {
        lazy[node] = 0;

        if (l == r)
        {
            tree[node] = prefEenrgy[l] - a[l].pos;
            return;
        }

        int mid = (l + r) / 2;

        build(2 * node, l, mid);
        build(2 * node + 1, mid + 1, r);

        tree[node] = max(tree[2 * node], tree[2 * node + 1]);
    }

    void pushLazy(int node, int l, int r)
    {
        tree[node] += lazy[node];

        if (l != r)
        {
            lazy[2 * node] += lazy[node];
            lazy[2 * node + 1] += lazy[node];
        }

        lazy[node] = 0;
    }

    void update(int node, int l, int r, int ql, int qr, long long delta)
    {
        pushLazy(node, l, r);

        if (l > qr || r < ql)
        {
            return;
        }

        if (ql <= l && r <= qr)
        {
            lazy[node] += delta;
            pushLazy(node, l, r);
            return;
        }

        int mid = (l + r) / 2;

        update(2 * node, l, mid, ql, qr, delta);
        update(2 * node + 1, mid + 1, r, ql, qr, delta);

        tree[node] = max(tree[2 * node], tree[2 * node + 1]);
    }

    long long query(int node, int l ,int r, int ql, int qr)
    {
        pushLazy(node, l, r);

        if (l > qr || r < ql)
        {
            return -inf;
        }

        if (ql <= l && r <= qr)
        {
            return tree[node];
        }

        int mid = (l + r) / 2;

        return max(query(2 * node, l, mid, ql, qr), query(2 * node + 1, mid + 1, r, ql, qr));
    }

    inline void build()
    {
        build(1, 1, n);
    }

    inline void update(int l, int r, long long delta)
    {
        update(1, 1, n, l, r, delta);
    }

    inline long long query(int l, int r)
    {
        return query(1, 1, n, l, r);
    }
};

SegmentTree tree;

bool check(long long targetGold)
{
    tree.build();

    //cout << "checking for " << targetGold << endl;

    for (int i = 1; i <= n; ++i)
    {
        if (a[i].gold >= targetGold)
        {
            return true;
        }

        int l = i + 1;
        int r = n;

        while (l <= r)
        {
            int mid = (l + r) / 2;

            if (prefGold[mid] - prefGold[i - 1] >= targetGold)
            {
                r = mid - 1;
            }
            else
            {
                l = mid + 1;
            }
        }

        //cout << i << " :: " << ptr << " " << currentSum << endl;

        int pos = l;

        if (pos > n)
        {
            break;
        }

        if (tree.query(pos, n) >= 0)
        {
            return true;
        }

        if (i + 1 <= n)
        {
            tree.update(i + 1, n, (a[i + 1].pos - a[i].pos) - a[i].energy);
        }
    }

    return false;
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n;

    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i].pos >> a[i].gold >> a[i].energy;
        prefEenrgy[i] = prefEenrgy[i - 1] + a[i].energy;
        prefGold[i] = prefGold[i - 1] + a[i].gold;
    }

    for (int i = 2; i <= n; ++i)
    {
        a[i].pos -= a[1].pos;
    }

    a[1].pos = 0;

    long long sum = 0;

    for (int i = 1; i <= n; ++i)
    {
        sum += a[i].gold;
    }

    long long l = 0;
    long long r = sum;

    while (l <= r)
    {
        long long mid = (l + r) / 2;

        if (check(mid) == true)
        {
            l = mid + 1;
        }
        else
        {
            r = mid - 1;
        }
    }

    cout << r << endl;

    return 0;
}

/*
4
0 5 1
1 7 2
4 4 1
7 15 1

4
1 5 1
2 7 2
5 4 1
8 15 1

2
2 4 1
5 5 1
*/

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct
6 Correct 1 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4440 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 1 ms 4444 KB Output is correct
11 Correct 1 ms 4440 KB Output is correct
12 Correct 1 ms 4440 KB Output is correct

Subtask #2
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct
6 Correct 1 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4440 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 1 ms 4444 KB Output is correct
11 Correct 1 ms 4440 KB Output is correct
12 Correct 1 ms 4440 KB Output is correct
13 Correct 1 ms 4440 KB Output is correct
14 Correct 1 ms 4444 KB Output is correct
15 Correct 3 ms 4440 KB Output is correct
16 Correct 2 ms 4444 KB Output is correct
17 Correct 4 ms 4444 KB Output is correct
18 Correct 1 ms 4444 KB Output is correct
19 Correct 1 ms 4444 KB Output is correct
20 Correct 1 ms 4444 KB Output is correct
21 Correct 4 ms 4444 KB Output is correct
22 Correct 10 ms 4632 KB Output is correct
23 Correct 35 ms 4732 KB Output is correct
24 Correct 34 ms 4700 KB Output is correct

Subtask #3
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 1 ms 4444 KB Output is correct
6 Correct 1 ms 4444 KB Output is correct
7 Correct 1 ms 4444 KB Output is correct
8 Correct 1 ms 4440 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 1 ms 4444 KB Output is correct
11 Correct 1 ms 4440 KB Output is correct
12 Correct 1 ms 4440 KB Output is correct
13 Correct 1 ms 4440 KB Output is correct
14 Correct 1 ms 4444 KB Output is correct
15 Correct 3 ms 4440 KB Output is correct
16 Correct 2 ms 4444 KB Output is correct
17 Correct 4 ms 4444 KB Output is correct
18 Correct 1 ms 4444 KB Output is correct
19 Correct 1 ms 4444 KB Output is correct
20 Correct 1 ms 4444 KB Output is correct
21 Correct 4 ms 4444 KB Output is correct
22 Correct 10 ms 4632 KB Output is correct
23 Correct 35 ms 4732 KB Output is correct
24 Correct 34 ms 4700 KB Output is correct
25 Correct 2 ms 4700 KB Output is correct
26 Correct 3 ms 6748 KB Output is correct
27 Correct 4 ms 6620 KB Output is correct
28 Correct 16 ms 6676 KB Output is correct
29 Correct 22 ms 6748 KB Output is correct
30 Correct 42 ms 8216 KB Output is correct
31 Correct 27 ms 8280 KB Output is correct
32 Correct 36 ms 8272 KB Output is correct
33 Correct 29 ms 8284 KB Output is correct
34 Correct 879 ms 8360 KB Output is correct
35 Execution timed out 1028 ms 8272 KB Time limit exceeded
36 Halted 0 ms 0 KB -