Submission #589800

#	Time	Username	Problem	Language	Result	Execution time	Memory
589800		Do_you_copy	Election (BOI18_election)	C++14	82 / 100	66 ms	5852 KiB

election

#include <bits/stdc++.h>
#define taskname "test"
#define fi first
#define se second
#define pb push_back
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
using ll = long long;
using pii = pair <int, int>;
using pil = pair <int, ll>;
using pli = pair <ll, int>;
using pll = pair <ll, ll>;
using ull = unsigned ll;
mt19937 Rand(chrono::steady_clock::now().time_since_epoch().count());

ll min(const ll &a, const ll &b){
    return (a < b) ? a : b;
}

ll max(const ll &a, const ll &b){
    return (a > b) ? a : b;
}

//const ll Mod = 1000000009;
//const ll Mod2 = 999999999989;
//only use when required
const int maxN = 1e5 + 1;

int n;
string s;

struct TNode{
    int pre, suf, sum, val;
    TNode operator + (TNode other){
        TNode tem;
        tem.val = max(max(val + other.sum, sum + other.val), pre + other.suf);
        tem.pre = max(pre, other.pre + sum);
        tem.suf = max(other.suf, suf + other.sum);
        tem.sum = sum + other.sum;
        return tem;
    }
};

TNode st[maxN * 4];
void build(int id = 1, int l = 1, int r = n){
    if (l == r){
        if (s[l - 1] == 'T') st[id] = {1, 1, 1, 1};
        else st[id] = {0, 0, -1, 0};

        return;
    }
    int m = (l + r) / 2;
    build(id * 2, l, m);
    build(id * 2 + 1, m + 1, r);
    st[id] = st[id * 2] + st[id * 2 + 1];
}

TNode get(int i, int j, int id = 1, int l = 1, int r = n){
    if (r < i || l > j) return {0, 0, 0, 0};
    if (i <= l && r <= j){
        return st[id];
    }
    int m = (l + r) / 2;
    return get(i, j, id * 2, l, m) + get(i, j, id * 2 + 1, m + 1, r);
}

void Init(){
    cin >> n >> s;
    int q; cin >> q;
    build();
    while (q--){
        int l, r;
        cin >> l >> r;
        cout << get(l, r).val << "\n";
    }
}


int main(){
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        //freopen(taskname".out", "w", stdout);
    }
    faster;
    ll tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
}

Compilation message (stderr)

election.cpp: In function 'int main()':
election.cpp:81:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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