Submission #933895

#	Time	Username	Problem	Language	Result	Execution time	Memory
933895		Whisper	Election (BOI18_election)	C++17	100 / 100	574 ms	74148 KiB

election

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define pii pair<int , int>
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 5e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
int nArr, numQuery;
string s;
struct SegTree{
    struct Node{
        int ans, sum, prf, suf;
        Node(): ans(0), sum(0), prf(0), suf(0){}
        Node(int x){
            sum = x;
            ans = max(0ll, x);
            prf = max(0ll, x);
            suf = max(0ll, x);
        }
        friend Node operator + (const Node& a, const Node& b){
            Node res;
            res.sum = a.sum + b.sum;
            res.prf = max(a.prf, a.sum + b.prf);
            res.suf = max(b.suf, b.sum + a.suf);
            res.ans = max({a.ans + b.sum, a.sum + b.ans, a.prf + b.suf});
            return res;
        }
    };
    vector<Node> st;
    int n;
    SegTree(int _n){
        this -> n = _n;
        st.resize((n << 2));
    }

    void BuildTree(int id, int l, int r){
        if (l == r){
            st[id] = Node((s[l] == 'C' ? -1 : 1));
            return;
        }
        int mid = (l + r) >> 1;
        BuildTree(id << 1, l, mid);
        BuildTree(id << 1 | 1, mid + 1, r);
        st[id] = st[id << 1] + st[id << 1 | 1];
    }

    Node query(int id, int l, int r, int u, int v){
        if (u > r || v < l) return Node(0);
        if (u <= l && v >= r) return st[id];
        int mid = (l + r) >> 1;
        Node ql = query(id << 1, l, mid, u, v);
        Node qr = query(id << 1 | 1, mid + 1, r, u, v);
        return (ql + qr);
    }
};
void Whisper(){
    cin >> nArr >> s;
    s = '@' + s;
    cin >> numQuery;
    SegTree st(nArr + 1);
    st.BuildTree(1, 1, nArr);
    for (int i = 1; i <= numQuery; ++i){
        int l, r; cin >> l >> r;
        cout << st.query(1, 1, nArr, l, r).ans << '\n';
    }
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

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