Submission #1123234

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123234		underwaterkillerwhale	Election (BOI18_election)	C++20	100 / 100	355 ms	22156 KiB

election

#include <bits/stdc++.h>
#define ll long long
#define rep(i, m, n) for (int i = (m); i <= (n); i++)
#define REB(i, m, n) for (int i = (m); i >= (n); i--)
#define iter(v, id) for (auto v : id)
#define pii pair<int, int>
#define pll pair<ll, ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define pb push_back
#define SZ(v) (int)v.size()
#define ALL(v) v.begin(), v.end()

using namespace std;

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }

const int N = 5e5 + 7;
const int Mod = 1e9 + 7;
const ll INF = 1e18 + 7;
const int BASE = 137;

int n, Q;
int a[N];

struct Segment_Tree {
    int m;
    struct Node {
        int pre, suf, S, A;
    };
    Node st[N << 2];

    Node mer (Node lc, Node rc) {
        Node cur;
        cur.pre = max(lc.pre, lc.S + rc.pre);
        cur.suf = max(rc.suf, rc.S + lc.suf);
        cur.S = lc.S + rc.S;
        cur.A = max({lc.A + rc.S, rc.A + lc.S, lc.pre + rc.suf});
        return cur;
    }

    void build (int id, int l, int r) {
        if (l == r) {
            st[id].pre = st[id].suf = st[id].A = max(0, a[l]);
            st[id].S = a[l];
            return;
        }
        int mid = l + r >> 1;
        build (id << 1, l, mid);
        build (id << 1 | 1, mid + 1, r);
        st[id] = mer (st[id << 1], st[id << 1 | 1]);
    }

    Node get (int id, int l, int r, int u, int v) {
        if (l > v || r < u) return {0, 0, 0, 0};
        if (l >= u && r <= v) return st[id];
        int mid = l + r >> 1;
        return mer (get (id << 1, l, mid, u, v), get (id << 1 | 1, mid + 1, r, u, v));
    }

    void init (int n) {
        m = n;
        build (1, 1, n);
    }

    int get (int u, int v) {
        return get (1, 1, m, u, v).A;
    }

}ST;

void process() {
    cin >> n;
    string s;
    cin >> s;
    rep (i, 1, n) a[i] = s[i - 1] == 'C' ? -1 : 1;
    ST.init(n);
    cin >> Q;
    rep (q, 1, Q) {
        int L, R;
        cin >> L >> R;
        cout << ST.get(L, R) <<"\n";
    }
}

#define file(name) if(fopen(name".inp","r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
main () {
//    file("c");
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--) {
        process();
    }
}
/*
onepunch +28
5 3
1 2 3 4 5
1 2
2 3
3 4
4 5
1 3
3 5
1 5

5 3
1 2 3 4 5
1 2
1 3
3 4
3 5
2 3
4 5
3 4

*/

Compilation message (stderr)

election.cpp:90:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   90 | main () {
      | ^~~~

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