Submission #877114

#	Time	Username	Problem	Language	Result	Execution time	Memory
877114		amin_2008	Election (BOI18_election)	C++17	0 / 100	14 ms	63068 KiB

election

#pragma GCC optimize ("O3")
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

// author: amin_2008

#define ios          ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define ll           long long
#define vi           vector<int>
#define vs           vector<string>
#define vc           vector<char>
#define vl           vector<ll>
#define all(v)       v.begin(), v.end()
#define rall(v)      v.rbegin(), v.rend()
#define pb           push_back
#define bpc          __builtin_popcount
#define pii          pair<int, int>
#define pll          pair<ll, ll>
#define piii         pair<pii, int>
#define vpii         vector<pii>
#define vpll         vector<pll>
#define vvpii        vector<vpii>
#define vvi          vector<vector<int>>
#define vvl          vector<vector<ll>>
#define ins          insert
#define ts           to_string
#define F            first
#define S            second
#define lb           lower_bound
#define ub           upper_bound
#define ld           long double
#define ull          unsigned long long
#define endl         '\n'
#define int          ll

using namespace std;
using namespace __gnu_pbds;
using namespace __cxx11;
template<class T> using ordered_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll inf = 2e5 * 1e9;
const int mod = 1e9+7;
const int sz = 5e5+5;
const int N = 1000003;
const int logg = 18;
const int P = 40000005;
const ll M = 8e5+5;

struct Node
{
    int sum, pref, suff, res;
};

int n, a[sz];

struct SegmentTree
{
    vector<Node> st;
    SegmentTree(int n)
    {
        st.resize(n << 2);
    }
    Node merge(Node a, Node b)
    {
        return {a.sum + b.sum, max(a.pref, a.sum + b.pref), max(b.suff, a.suff + b.sum),
        max({0LL, a.pref + b.suff, a.res, b.res, a.res + b.sum})};
    }
    void build(int l, int r, int in)
    {
        if (l == r)
        {
            st[in] = { a[l], max(0LL, a[l]), max(0LL, a[l]), max(a[l], 0LL) };
            return;
        }
        int mid = (l + r) >> 1;
        build(l, mid, in << 1);
        build(mid + 1, r, in << 1 | 1);
        st[in] = merge(st[in << 1], st[in << 1 | 1]);
    }
    Node get(int a, int b, int l, int r, int in)
    {
        if (l > b || r < a)         return {0, 0, 0, 0};
        if (a <= l && r <= b)       return st[in];
        int mid = (l + r) >> 1;
        return merge(get(a, b, l, mid, in << 1), get(a, b, mid + 1, r, in << 1 | 1));
    }
} st(sz);

void solve()
{
    string s;
    cin >> n >> s;
    for (int i = 0; i < n; i++)
        a[i] = (s[i] == 'C' ? -1 : 1);
    st.build(0, n - 1, 1);
    int q;
    cin >> q;
    while (q--)
    {
        int x, y;
        cin >> x >> y;
        Node result = st.get(--x, --y, 0, n - 1, 1);
        cout << result.res << endl;
    }
}

signed main()
{
    ios;
    //precompute();
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18