oj.uz

Submission #414220

# Submission time Handle Problem Language Result Execution time Memory
414220 2021-05-30T09:20:20 Z shivensinha4 Election (BOI18_election) C++17
100 / 100
 810 ms 49856 KB 
#include <bits/stdc++.h>
using namespace std;
#define for_(i, s, e) for (int i = s; i < (int) e; i++)
#define for__(i, s, e) for (ll i = s; i < e; i++)
typedef long long ll;
typedef vector<int> vi;
typedef array<int, 2> ii;
#define endl '\n'

struct Node {
    int pref = 0, sum = 0;
};

class SegmentTree {
private:
    vector<Node> tree; int n;
    Node bound = {0, 0};

    static Node merge(Node a, Node b) {
        Node ans;
        ans.sum = a.sum + b.sum;
        ans.pref = max(a.pref, a.sum + b.pref);
        return ans;
    }

    void update(int i, int val, int l, int r, int p) {
        if (l > i or r < i) return;
        if (l == r) {
            tree[p] = {val, val};
            return;
        }

        int mid = (l + r) / 2;
        int c1 = 2*p+1, c2 = 2*p+2;
        update(i, val, l, mid, c1); update(i, val, mid+1, r, c2);
        tree[p] = merge(tree[c1], tree[c2]);
    }

    Node mx(int i, int j, int l, int r, int p) {
        if (l > j or r < i) return bound;
        if (l >= i and r <= j) return tree[p];

        int mid = (l + r) / 2;
        int c1 = 2*p+1, c2 = 2*p+2;
        return merge(mx(i, j, l, mid, c1), mx(i, j, mid+1, r, c2));
    }

public:
    SegmentTree(int _n) {
        n = _n;
        tree.resize(4*n, bound);
    }

    Node mx(int i, int j) {
        return mx(i, j, 0, n-1, 0);
    }

    void update(int i, int val) {
        update(i, val, 0, n-1, 0);
    }
};

// Ask for sum 1 -> n for full (one based indexing)
class BIT {
private: vector<ll> tree; int n;
    int LSOne(int x) {
        return x&(-x);
    }

public:
    BIT(int x) {
        n = x;
        tree.resize(n+1);
    }
    ll sum(int a) {
        ll sum = 0;
        for (; a > 0; a -= LSOne(a)) sum += tree[a];
        return sum;
    }
    ll sum(int a, int b) {
        return sum(b) - (a == 1 ? 0 : sum(a-1));
    }
    void update(int p, ll v) {
        for (; p < n+1; p += LSOne(p)) tree[p] += v;
    }
};


int main() {
#ifdef mlocal
    freopen("test.in", "r", stdin);
#endif

    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n; cin >> n;
    vi nums(n);
    for_(i, 0, n) {
        char c; cin >> c;
        nums[i] = c == 'C' ? 1 : -1;
    }


    int q; cin >> q;
    vector<vector<ii>> ends(n);
    for_(i, 0, q) {
        int l, r; cin >> l >> r;
        ends[l-1].push_back({r-1, i});
    }

    vi out(q);
    stack<int, vi> st;

    SegmentTree tree(n);
    BIT negpref(n);

    for (int i = n-1; i >= 0; i--) {
        if (nums[i] == -1) {
            negpref.update(i+1, 1);
            st.push(i);
        }
        else {
            tree.update(i, 1);
            if (st.size()) {
                negpref.update(st.top()+1, -1);
                tree.update(st.top(), -1);
                st.pop();
            }
        }

        for (auto &r: ends[i]) {
            Node temp = tree.mx(i, r[0]);
            out[r[1]] = temp.pref - temp.sum + negpref.sum(r[0]+1);
        }

    }

    for (auto i: out) cout << i << endl;
    cout << endl;

//    cout << ans + tree.mx(0, n-1) - tree.tree[0].sum << endl;
}

Subtask #1
28.0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 460 KB Output is correct
2 Correct 3 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 3 ms 460 KB Output is correct
5 Correct 3 ms 460 KB Output is correct

Subtask #2
54.0 / 54.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 460 KB Output is correct
2 Correct 3 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 3 ms 460 KB Output is correct
5 Correct 3 ms 460 KB Output is correct
6 Correct 91 ms 6988 KB Output is correct
7 Correct 70 ms 6532 KB Output is correct
8 Correct 68 ms 6532 KB Output is correct
9 Correct 71 ms 6808 KB Output is correct
10 Correct 81 ms 6848 KB Output is correct
11 Correct 72 ms 7164 KB Output is correct
12 Correct 71 ms 7000 KB Output is correct
13 Correct 89 ms 7260 KB Output is correct
14 Correct 89 ms 7044 KB Output is correct
15 Correct 90 ms 6988 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 460 KB Output is correct
2 Correct 3 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 3 ms 460 KB Output is correct
5 Correct 3 ms 460 KB Output is correct
6 Correct 91 ms 6988 KB Output is correct
7 Correct 70 ms 6532 KB Output is correct
8 Correct 68 ms 6532 KB Output is correct
9 Correct 71 ms 6808 KB Output is correct
10 Correct 81 ms 6848 KB Output is correct
11 Correct 72 ms 7164 KB Output is correct
12 Correct 71 ms 7000 KB Output is correct
13 Correct 89 ms 7260 KB Output is correct
14 Correct 89 ms 7044 KB Output is correct
15 Correct 90 ms 6988 KB Output is correct
16 Correct 713 ms 48056 KB Output is correct
17 Correct 612 ms 44548 KB Output is correct
18 Correct 668 ms 45236 KB Output is correct
19 Correct 605 ms 47012 KB Output is correct
20 Correct 722 ms 47152 KB Output is correct
21 Correct 745 ms 49448 KB Output is correct
22 Correct 810 ms 49008 KB Output is correct
23 Correct 715 ms 49856 KB Output is correct
24 Correct 711 ms 49104 KB Output is correct
25 Correct 684 ms 48248 KB Output is correct