Submission #497480

#	Time	Username	Problem	Language	Result	Execution time	Memory
497480		armashka	Bigger segments (IZhO19_segments)	C++17	0 / 100	0 ms	332 KiB

segments

#include <bits/stdc++.h>
 
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define fast ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
#define all(v) v.begin(),v.end()
#define pb push_back
#define sz size()
#define ft first
#define sd second
 
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef unsigned long long ull;
 
const int N = 1e6 + 5;
const ll M = 1e8;
const ll inf = 1e18;
const ll mod = 1e9;
const double Pi = acos(-1); 
 
ll binpow(ll x, ll ti) { ll res = 1;while (ti){if(ti & 1)res *= x;x *= x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll binmul(ll x, ll ti) { ll res = 0;while (ti){if(ti & 1)res += x;x += x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll nok(ll a, ll b) { return (a*b)/__gcd(abs(a),abs(b)) * (a*b > 0 ? 1 : -1); }
bool odd(ll n) { return (n % 2 == 1); }
bool even(ll n) { return (n % 2 == 0); }            

struct dinamike {
	ll cnt = 0, sum = 0;
} dp[N], t[N * 4], fl[N * 4];

ll n, a[N], pr[N], l[N];

const void solve(/*Armashka*/) {
	cin >> n;
	for (int i = 1; i <= n; ++ i) {
		cin >> a[i];
		pr[i] = pr[i - 1] + a[i];
		dp[i] = {1, pr[i]};
	}
	l[1] = 1;
	ll cur = 1;
	for (int i = 2; i <= n; ++ i) {
		ll le = l[cur], r = i, j = -1;
		
		while (le <= r) {
			ll mid = (le + r) / 2;
			if (pr[i] - pr[mid - 1] >= pr[mid - 1] - pr[l[cur] - 1]) le = mid + 1, j = mid;
			else r = mid - 1;	
		}
		//cout << j << " " << i << " -> ";
		r = i; le = j; j = -1;
		while (le <= r) {
			ll mid = (le + r) / 2;
			if (pr[mid] - pr[l[cur] - 1] >= dp[l[cur] - 1].sum) r = mid - 1, j = mid;
			else le = mid + 1;
		}
		
		if (j == -1) {
			dp[i] = {cur, pr[i] - pr[l[cur] - 1]};
		} else {
			dp[i] = {dp[j - 1].cnt + 1, pr[i] - pr[j - 1]};
			dp[j - 1].sum = pr[j - 1] - pr[l[cur] - 1];
			if (l[dp[i].cnt] == 0) l[dp[i].cnt] = j;
		}
		//cout << j << " " << i << "\n";
		cur = dp[i].cnt;
	}
	//for (int i = 1; i <= n; ++ i) cout << dp[i].sum << " ";
	cout << dp[n].cnt << "\n";
}
            
signed main() {
    fast;
    //freopen("divide.in", "r", stdin);
    //freopen("divide.out", "w", stdout);
    int tt = 1;
    //cin >> tt;
    while (tt --) {                                                
        solve();
    }
}
 
/*
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1
*/

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27