Submission #836712

#	Time	Username	Problem	Language	Result	Execution time	Memory
836712		abysmal	Election (BOI18_election)	C++14	100 / 100	422 ms	28012 KiB

election

#include<iostream>
#include<stdio.h>
#include<stdint.h>
#include<iomanip>
#include<algorithm>
#include<utility>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<deque>
#include<math.h>
#include<assert.h>
#include<string.h>

using namespace std;

const int64_t INF = (int64_t) 1e18 + 100;
const int64_t mINF = (int64_t) 1e6 * 2 + 100;
const int64_t MOD = 1e9 + 7;
const int64_t MOD2 = 998244353;
const int nbit = 31;
const int ndig = 10;
const int nchar = 26;
const int D = 4;
int dr[D] = {-1, 0, 1, 0};
int dc[D] = {0, 1, 0, -1};
const int Dk = 8;
int drk[Dk] = {2, 2, -2, -2, 1, 1, -1, -1};
int dck[Dk] = {1, -1, 1, -1, 2, -2, 2, -2};

struct Node
{
    int mx;
    int sum;
    int pre;
    int suf;

    Node(int mx_, int sum_, int pre_, int suf_) : mx(mx_), sum(sum_), pre(pre_), suf(suf_) {}
};

struct Solution
{
    int n;
    string s;
    vector<Node> tree;
    Solution() {}

    void solve()
    {
        cin >> n >> s;
        while(__builtin_popcount(n) != 1) n++;
        tree.resize(2 * n, Node(0, 0, 0, 0));

        for(int i = 0; i < (int) s.length(); i++)
        {
            if(s[i] == 'T') tree[n + i] = Node(1, 1, 1, 1);
            else tree[n + i] = Node(0, -1, 0, 0);
        }

        for(int i = n - 1; i >= 1; i--)
        {
            tree[i] = combine(tree[i * 2], tree[i * 2 + 1]);
        }

        int q;
        cin >> q;
        for(int i = 0; i < q; i++)
        {
            int l;
            int r;
            cin >> l >> r;
            l--; r--;

            cout << get(1, 0, n - 1, l, r).mx << "\n";
        }
    }

    Node get(int node, int nleft, int nright, int left, int right)
    {
        if(left > nright || nleft > right) return Node(0, 0, 0, 0);
        if(left <= nleft && nright <= right) return tree[node];

        int mid = nleft + (nright - nleft) / 2;
        return combine(get(node * 2, nleft, mid, left, right),
                       get(node * 2 + 1, mid + 1, nright, left, right));
    }

    Node combine(Node left, Node right)
    {
        Node now(0, 0, 0, 0);
        now.sum = left.sum + right.sum;
        now.pre = max(left.pre, left.sum + right.pre);
        now.suf = max(right.suf, right.sum + left.suf);
        now.mx = max({left.mx + right.sum, left.sum + right.mx, left.pre + right.suf});
        return now;
    }

    void modadd(int& t1, int t2)
    {
        t1 += t2;
        if(t1 >= MOD) t1-= MOD;
        return;
    }

    void modsub(int& t1, int t2)
    {
        t1 -= t2;
        if(t1 < 0) t1 += MOD;
        return;
    }

    int modmul(int t1, int t2)
    {
        int64_t res = 1LL * t1 * t2;
        return res % MOD;
    }

    int Abs(int tmp)
    {
        if(tmp < 0) return -tmp;
        return tmp;
    }

    int MASK(int j)
    {
        return (1 << j);
    }

    int BIT(int tmp, int j)
    {
        int x = tmp & MASK(j);
        if(x != 0) return 1;
        return 0;
    }
};

void __setup()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

//    freopen("in.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);
}

int main()
{
    __setup();

    int t = 1;
//    cin >> t;
    for(int i = 1; i <= t; i++)
    {
        Solution().solve();
    }
    return 0;
}

• Subtask 1: 28 / 28
• Subtask 2: 54 / 54
• Subtask 3: 18 / 18