Submission #571644

#	Time	Username	Problem	Language	Result	Execution time	Memory
571644		nttt	Election (BOI18_election)	C++14	0 / 100	2 ms	340 KiB

election

#include<bits/stdc++.h>
using namespace std;
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x >> (i)) & 1)
#define fi first
#define se second
#define ll long long
#define task "name" 

const int oo = 1e9 + 7;
const ll loo = (ll)1e18 + 7;
const int MOD = 1e9 + 7;
const int N = 5e5 + 3;
const int BASE = 10;

template <typename T1, typename T2> bool minimize(T1 &a, T2 b)
{
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b)
{
    if (a < b) {a = b; return true;} return false;
}

struct nodes
{
    int sum = 0;
    int pr = 0;
    int sf = 0;
    int ans = 0;
} node[4 * N], base;
int n;
string s;
nodes add(nodes a, nodes b) 
{
	nodes c;
	c.sum = a.sum + b.sum;
	c.pr = max(a.pr, a.sum + b.pr);
	c.sf = max(b.sf, b.sum + a.sf);
	// c.ans = max(a.sum + b.ans, a.ans + b.sum);
	// c.ans = max(c.ans, a.pr + b.sf);
    c.ans = max(a.pr + b.pr, a.sf + b.sf);
	return c;
}
void build(int id, int l, int r, int pos, int x)
{
    if(l > r || pos < l || r < pos) return;
    if (l == r) 
    {
	    node[id].sum = x;
		maximize(node[id].pr, x);
		maximize(node[id].sf, x);
		maximize(node[id].ans, x);
		return;
	}
    int mid = (l + r)/2;
	build(id * 2, l, mid, pos, x);
    build(id * 2 + 1, mid + 1, r, pos, x);
	node[id] = add(node[id * 2], node[id * 2 + 1]);
}

nodes get(int id, int l, int r, int u, int v)
{
    if (r < u || v < l) return base;
	if (u <= l && r <= v) return node[id];
    int mid = (l + r)/2;
	return add(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    //freopen(task".inp" , "r" , stdin);
    //freopen(task".out" , "w" , stdout);
    
    cin >> n >> s;
    for (int i = 0; i < n; i++)
    {
        if(s[i] == 'T') build(1, 1, n, i + 1, 1);
        else build(1, 1, n, i + 1, -1);
    }
    int q;
    cin >> q;
    while(q--)
    {
        int l, r;
        cin >> l >> r;
        cout << get(1, 1, n, l, r).ans << '\n';
    }

    return 0;
}

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