제출 #628709

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
628709		BackNoob	Bigger segments (IZhO19_segments)	C++14	100 / 100	137 ms	24708 KiB

segments

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
 
using namespace std;
const int mxN = 5e5 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
 
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 FenwickTree{
	int n;
	vector<int> bit;
	FenwickTree(){}
	FenwickTree(int _n) {
		n = _n;
		bit.resize(n + 7, -inf);
	}

	void update(int pos, int val)
	{
		for(; pos <= n; pos += pos & -pos) maximize(bit[pos], val);
	}
	int getmax(int pos)
	{
		int res = -inf;
		for(; pos > 0; pos -= pos & -pos) res = max(res, bit[pos]);
		return res;
	}

} ft;

 
int n;
int a[mxN];
ll pre[mxN];
pair<ll, int> dp[mxN];
vector<ll> val;

int getpos(ll x)
{
	return lower_bound(all(val), x) - val.begin() + 1;
}
 
void solve()
{
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> a[i];

	for(int i = 1; i <= n; i++) pre[i] = pre[i - 1] + a[i];
	for(int i = 0; i <= n; i++) val.pb(pre[i]);
	sort(all(val));
	val.erase(unique(all(val)), val.end());

	ft = FenwickTree(sz(val));
	ft.update(getpos(pre[0]), 0);

	dp[0] = {0, 0};
	for(int i = 1; i <= n; i++) {
		
		int p = getpos(pre[i]);
		int j = ft.getmax(p);
		dp[i] = {pre[i] - pre[j], dp[j].se + 1};

		int pp = getpos(dp[i].fi + pre[i]);
		ft.update(pp, i);
	}

	cout << dp[n].se;
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

 
    int tc = 1;
    //cin >> tc;
    while(tc--) {
    	solve();
    }
    return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27