제출 #1209046

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1209046		vanea	Election (BOI18_election)	C++20	0 / 100	1 ms	320 KiB

election

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const int mxN = 2e6+10;
string s;
array<int, 4> st[mxN];

array<int, 4> comb(array<int, 4> a, array<int, 4> b) {
    array<int, 4> ans = {0, 0, 0, 0};
    ans[1] = a[1] + b[1];
    ans[2] = max(a[2], a[1] + b[2]);
    ans[3] = max(b[3], b[1] + a[3]);
    ans[4] = max(ans[3], ans[2]);
    return ans;
}

void build(int node, int l, int r) {
    if(l == r) {
        int curr = s[l] == 'C' ? -1 : 1;
        st[node] = {curr, curr, curr, curr};
        return ;
    }
    int mid = (l+r)/2;
    build(node*2, l, mid);
    build(node*2+1, mid+1, r);
    st[node] = comb(st[node*2], st[node*2+1]);
}

array<int, 4> qry(int node, int l, int r, int l1, int r1) {
    if(l1 <= l && r <= r1) {
        return st[node];
    }
    if(l > r1 || r < l1) return {0,0,0,0};
    int mid = (l+r)/2;
    return comb(qry(node*2, l, mid, l1, r1),
                qry(node*2+1, mid+1, r, l1, r1));
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n;
    cin >> n;
    cin >> s;
    int q;
    cin >> q;
    build(1, 0, n-1);
    while(q--) {
        int l, r;
        cin >> l >> r;
        --l; --r;
        array<int, 4> now = qry(1, 0, n-1, l, r);
        cout << now[3] << '\n';
    }
    return 0;
}

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