제출 #522765

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
522765		nafis_shifat	Bigger segments (IZhO19_segments)	C++17	100 / 100	399 ms	53644 KiB

segments

#include<bits/stdc++.h>
#define ll long long
#define pii pair<ll,ll>
using namespace std;
const int mxn=1e6+5;
const int inf=1e9;
pii dp[mxn];
ll a[mxn], pre[mxn];
int n;

struct segtree {
	pii lazy[4 * mxn] = {};
	pii tree[4 * mxn] = {};
	


	void propogate(int node) {
		int left=node<<1;
		int right=left|1;

		tree[left] = max(tree[left], lazy[node]);
		tree[right] = max(tree[right], lazy[node]);
		lazy[left] = max(lazy[left], lazy[node]);
		lazy[right] = max(lazy[right], lazy[node]);
		lazy[node] = {0, 0};
	}

	void update(int node,int b,int e,int l,int r,pii v) {
		if(e<l || b>r)return;
		if(b>=l && e<=r) {
			tree[node] = max(tree[node], v);
			lazy[node] = max(lazy[node], v);
			return;
		}
		if(lazy[node]!= make_pair(0ll, 0ll)) propogate(node);

		int mid=b+e>>1;
		int left=node<<1;
		int right=left|1;

		update(left,b,mid,l,r,v);
		update(right,mid+1,e,l,r,v);
		tree[node]=max(tree[left],tree[right]);
	}

	pii query(int node, int b, int e, int p) {
		if(b == e) return tree[node];

		int mid = b + e >> 1;
		int left = node << 1;
		int right = left | 1;
		if(lazy[node] != make_pair(0ll, 0ll)) propogate(node);
		if(p <= mid) return query(left, b, mid, p);
		return query(right, mid + 1, e, p);
	}
} st;
int main() {
	cin >> n;
	pre[0] = 0;
	for(int i = 1; i <= n; i++) {
		cin >> a[i];
		pre[i] = pre[i - 1] + a[i];
	}

	dp[0] = {0, 0};

	for(int i = 1; i <= n; i++) {
		dp[i] = {1, pre[i]};
		auto x = st.query(1, 1, n, i);
		dp[i] = max(dp[i], {x.first, pre[i] - x.second});


		int lo = i + 1;
		int hi = n;
		int ind = n + 1;
		while(lo <= hi) {
			int mid = lo + hi >> 1;
			if(pre[mid] >= dp[i].second + pre[i]) {
				ind = mid;
				hi = mid - 1;
			} else {
				lo = mid + 1;
			}
		}

		st.update(1, 1, n, ind, n, make_pair(dp[i].first + 1ll, pre[i]));


	}

	cout<<dp[n].first<<endl;
	
}

컴파일 시 표준 에러 (stderr) 메시지

segments.cpp: In member function 'void segtree::update(int, int, int, int, int, std::pair<long long int, long long int>)':
segments.cpp:37:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   37 |   int mid=b+e>>1;
      |           ~^~
segments.cpp: In member function 'std::pair<long long int, long long int> segtree::query(int, int, int, int)':
segments.cpp:49:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   49 |   int mid = b + e >> 1;
      |             ~~^~~
segments.cpp: In function 'int main()':
segments.cpp:77:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   77 |    int mid = lo + hi >> 1;
      |              ~~~^~~~

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