Submission #685412

#	Time	Username	Problem	Language	Result	Execution time	Memory
685412		OrazB	Bigger segments (IZhO19_segments)	C++14	0 / 100	1 ms	468 KiB

segments

#include <bits/stdc++.h>
#define N 100005
#define wr cout << "Continue debugging\n";
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second
using namespace std;

int a[N], mx, n, c[N];
ll pref[N], lazy[4*N], t[4*N];
ll dp[N][5];

int binary(int i, int x){
	int l = i+1, r = n, idx=i;
	while(l <= r){
		int md = (l+r)/2;
		if (pref[md]-pref[i] >= x) r = md - 1;
		else{
			idx = md;
			l = md + 1;
		}
	}
	return idx+1;
}
void upd(int x, int u, int v, int l, int r, int idx){
	if (lazy[idx]){
		t[idx] = lazy[idx];
		// if (l == 3 and r == 3 and x == 2) wr;
		if (l != r){
			lazy[idx*2] = lazy[idx];
			lazy[idx*2+1] = lazy[idx]; 
		}
		lazy[idx] = 0;
	}
	if (l > r or l > v or r < u) return;
	// if (l == 2 and r == 2) wr
	if (u <= l and r <= v){
		// cout << l << " " << r;
		t[idx] = x;
		if (l != r){
			lazy[idx*2] = x;
			lazy[idx*2+1] = x; 
		}
		return;
	}
	int md = (l+r)/2;
	upd(x, u, v, l, md, idx*2);
	upd(x, u, v, md+1, r, idx*2+1);
	// if (l != r)
	t[idx] = max(t[idx*2], t[idx*2+1]);
}
int range(int pos, int l, int r, int idx){
	if (lazy[idx]){
		t[idx] = lazy[idx];
		if (l != r){
			lazy[idx*2] = lazy[idx];
			lazy[idx*2+1] = lazy[idx]; 
		}
		lazy[idx]=0;
	}
	int md = (l+r)/2;
	if (l == r) return t[idx];
	if (md >= pos) range(pos, l, md, idx*2);
	else range(pos, md+1, r, idx*2+1);
	// t[idx] = max(t[idx*2], t[idx*2+1]);
}
int main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++){
		cin >> a[i];
		pref[i] = pref[i-1]+a[i];
	}
	dp[1][1] = 1;
	dp[1][2] = a[1];
	int pos = binary(1, a[1]);
	// cout << pos;
	if (pos <= n) upd(1, pos, n, 1, n, 1);
	// upd(1, n, n, 1, n, 1);
	// cout << range(3, 1, n, 1);
	for (int i = 2; i <= n; i++){
		int pos = range(i, 1, n, 1);
		// if (i == 3) cout << pos;
		if (!pos){
			dp[i][1] = 1;
			dp[i][2] = pref[i];
		}else{
			dp[i][1] = dp[pos][1]+1;
			dp[i][2] = pref[i]-pref[pos];
		}
		pos = binary(i, dp[i][2]);
		if (pos <= n) upd(i, pos, n, 1, n, 1);
		// if (i == 2) cout << range(3, 1, n, 1);
	}
	cout << dp[n][1];
}	

Compilation message (stderr)

segments.cpp: In function 'int range(int, int, int, int)':
segments.cpp:69:1: warning: control reaches end of non-void function [-Wreturn-type]
   69 | }
      | ^

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