Submission #96563

#	Time	Username	Problem	Language	Result	Execution time	Memory
96563		josiftepe	Election (BOI18_election)	C++14	100 / 100	1824 ms	58528 KiB

election

#include <bits/stdc++.h>

using namespace std;
const int maxn = 5e5 + 10;
int n;
string s;
bool visited[maxn];
int arr[maxn];
int solve(int S, int E){
    int balance = 0;
    int ret = 0;
    memset(visited, false, sizeof visited);
    for(int i = S; i <= E; i ++){
        if(s[i] == 'C'){
            balance ++;
            arr[i] = 1;
        }
        else{
            balance --;
            arr[i] = -1;
        }

        if(balance < 0){
            balance = 0;
            visited[i] = true;
           // arr[i] = 0;
            ret ++;
        }

    }
    int suff_sum = 0;
    int mnn = (1 << 30);
    for(int i = S; i <= S; i ++){
        suff_sum += arr[i];
    //    mnn = min(mnn, min(0, -suff_sum));
    }
    balance = 0;
    for(int i = E; i >= S; i --){
        if(s[i] == 'C'){
            balance ++;
        }
        else if(!visited[i] and s[i] == 'T'){
            balance --;
        }
      //  cout << balance << " " ;
        mnn = min(mnn, min(0, -balance));
        if(balance < 0){
            balance = 0;
//            ret ++;
        }
    }
    return ret + abs(mnn);
}
struct elem{
    int L, R, sum, min_suf;
    elem(){
        L = R = sum = min_suf = 0;
    }
};
elem mymerge(elem A, elem B){
    elem ret;
    ret.R = max(A.R, B.R - A.min_suf);
    ret.sum = max(B.sum, A.sum - B.min_suf);
    ret.min_suf = A.min_suf + B.min_suf;
    ret.L = max(max(A.L - B.min_suf, B.L - A.min_suf), A.R + B.sum);
    return ret;
}
class node{
public:
    elem val;
    int lb, rb;
    node *left, *right;
    node(int levo, int desno){
        lb = levo;
        rb = desno;
        if(levo == desno){
            if(s[levo] == 'T'){
                val.L = val.R = val.sum = 1;
                val.min_suf = -1;
            }
            else{
                val.L = val.R = val.sum = 0;
                val.min_suf = 1;
            }
        }
        else{
            int mid = (levo + desno) >> 1;
            left = new node(levo, mid);
            right = new node(mid + 1, desno);
            val = mymerge(left -> val, right -> val);
        }

    }
    elem query(int i, int j){
        if(i <= lb and rb <= j){
            return val;
        }
        /// i j l r i j
        if(j < lb or rb < i){
            return elem();
        }
        return mymerge(left -> query(i, j), right -> query(i, j));
    }
};
int main()
{
    ios_base::sync_with_stdio(false);
    //ifstream cin("in.txt.txt");
    cin >> n >> s;
    int q;
    cin >> q;
    node *root = new node(0, n - 1);
    for(int i = 0; i < q; i ++){
        int a, b;
        cin >> a >> b;
        a --;
        b --;
        cout << root -> query(a, b).L << endl;
    }
    return 0;
}

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