Submission #567734

#	Time	Username	Problem	Language	Result	Execution time	Memory
567734		Tam_theguide	Election (BOI18_election)	C++14	100 / 100	644 ms	27488 KiB

election

#include <bits/stdc++.h>
using namespace std;
int n, q;
struct node{
    int p;
    int s;
    int t;
    int a;
};
node seg[2310000];
node combine(node x, node y){
    node re;
    re.p = max(x.p, x.t + y.p);
    re.s = max(y.s, y.t + x.s);
    re.t = x.t + y.t;
    re.a = max(x.p + y.s, max(x.a + y.t, y.a + x.t));
    return re;
}
void update(int root, int tl, int tr, int pos, int val){
    if (tl == tr){
        seg[root].p = max(seg[root].p, val);
        seg[root].s = max(seg[root].s, val);
        //seg[root].p = val; seg[root].s = val;
        seg[root].t += val;
        seg[root].a = ((val == -1) ? 0 : 1);
        return;
    }
    int tm = (tl + tr) / 2;
    if (pos <= tm) update(2 * root, tl, tm, pos, val);
    else update(2 * root + 1, tm + 1, tr, pos, val);
    seg[root] = combine(seg[2 * root], seg[2 * root + 1]);
}
node query(int root, int tl, int tr, int l, int r){
    if (tl > r || tr < l) return {0, 0, 0, 0};
    if (tl >= l && tr <= r) return seg[root];
    int tm = (tl + tr) / 2;
    return combine(query(2 * root, tl, tm, l, r), query(2 * root + 1, tm + 1, tr, l, r));
}
int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n;

    for (int i = 1;i <= n;i ++){
        char x; cin >> x;
        update(1, 1, n, i, ((x == 'C') ? -1 : 1));
    }

    cin >> q;
    while (q--){
        int l, r; cin >> l >> r;
        cout << query(1, 1, n, l, r).a << '\n';
    }
}
/*
3
TCT
3
1 1
2 2
1 2
*/

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