Submission #702343

#	Time	Username	Problem	Language	Result	Execution time	Memory
702343		stevancv	Election (BOI18_election)	C++14	100 / 100	852 ms	50008 KiB

election

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 5e5 + 2;
const int inf = 2e9;
int a[N], p[N], n;
int st[4 * N], lzy[4 * N];
void Init(int node, int l, int r) {
    if (l == r) {
        st[node] = p[l];
        return;
    }
    int mid = l + r >> 1;
    Init(2 * node, l, mid);
    Init(2 * node + 1, mid + 1, r);
    st[node] = max(st[2 * node], st[2 * node + 1]);
}
void Propagate(int node, int l, int r) {
    if (lzy[node] == 0) return;
    if (l < r) {
        lzy[2 * node] += lzy[node];
        lzy[2 * node + 1] += lzy[node];
    }
    st[node] += lzy[node];
    lzy[node] = 0;
}
void Add(int node, int l, int r, int ql, int qr, int x) {
    Propagate(node, l, r);
    if (r < ql || qr < l || ql > qr) return;
    if (ql <= l && r <= qr) {
        lzy[node] += x;
        Propagate(node, l, r);
        return;
    }
    int mid = l + r >> 1;
    Add(2 * node, l, mid, ql, qr, x);
    Add(2 * node + 1, mid + 1, r, ql, qr, x);
    st[node] = max(st[2 * node], st[2 * node + 1]);
}
int Get(int node, int l, int r, int ql, int qr) {
    Propagate(node, l, r);
    if (r < ql || qr < l) return -inf;
    if (ql <= l && r <= qr) return st[node];
    int mid = l + r >> 1;
    return max(Get(2 * node, l, mid, ql, qr), Get(2 * node + 1, mid + 1, r, ql, qr));
}
vector<int> qq[N], stk;
void Do(int x) {
    stk.push_back(x);
    Add(1, 1, n, x, n, -1);
}
void Undo() {
    if (stk.size() == 0) return;
    int x = stk.back(); stk.pop_back();
    Add(1, 1, n, x, n, 1);
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    string s; cin >> s;
    for (int i = 1; i <= n; i++) {
        if (s[i - 1] == 'C') a[i] = -1;
        else a[i] = 1;
        p[i] = p[i - 1] + a[i];
    }
    Init(1, 1, n);
    int q; cin >> q;
    vector<int> l(q), r(q), ans(q);
    for (int i = 0; i < q; i++) {
        cin >> l[i] >> r[i];
        qq[r[i]].push_back(i);
    }
    for (int i = 1; i <= n; i++) {
        if (s[i - 1] == 'T') Do(i);
        else Undo();
        for (int j : qq[i]) {
            int o = Get(1, 1, n, l[j], r[j]);
            if (l[j] >= 2) o -= Get(1, 1, n, l[j] - 1, l[j] - 1);
            int u = (int)(lower_bound(stk.begin(), stk.end(), l[j]) - stk.begin());
            ans[j] = stk.size() - u + max(o, 0);
        }
    }
    for (int i = 0; i < q; i++) cout << ans[i] << en;
    return 0;
}

Compilation message (stderr)

election.cpp: In function 'void Init(int, int, int)':
election.cpp:18:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   18 |     int mid = l + r >> 1;
      |               ~~^~~
election.cpp: In function 'void Add(int, int, int, int, int, int)':
election.cpp:40:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |     int mid = l + r >> 1;
      |               ~~^~~
election.cpp: In function 'int Get(int, int, int, int, int)':
election.cpp:49:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   49 |     int mid = l + r >> 1;
      |               ~~^~~

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