Submission #951619

#	Time	Username	Problem	Language	Result	Execution time	Memory
951619		pcc	Fish 2 (JOI22_fish2)	C++17	25 / 100	1054 ms	11388 KiB

fish2

#include <bits/stdc++.h>
using namespace std;

#define pii pair<int,int>
#define ll long long
#define pll pair<ll,ll>
#define fs first
#define sc second

const int mxn = 1e5+10;

int N,Q;
ll arr[mxn];

namespace S1{

	int calc(vector<int> &v){
		int ans = 0;
		for(int i = 0;i<v.size();i++){
			int l = i,r = i;
			ll sum = v[i];
			while((l>0&&sum>=v[l-1])||(r+1<v.size()&&sum>=v[r+1])){
				if(l>0&&sum>=v[l-1]){
					l--;
					sum += v[l];
				}
				else{
					r++;
					sum += v[r];
				}
			}
			if(l == 0&&r+1 == v.size())ans++;
		}
		return ans;
	}

	void solve(){
		while(Q--){
			int l,r,t;
			cin>>t>>l>>r;
			if(t == 1){
				arr[l] = r;
				continue;
			}
			vector<int> v;
			for(int i = l;i<=r;i++)v.push_back(arr[i]);
			cout<<calc(v)<<'\n';
		}
		return;
	}
}

namespace S2{
	pii seg[mxn*4];

#define ls now*2+1
#define rs now*2+2
#define mid ((l+r)>>1)
	void build(int now,int l,int r){
		if(l == r){
			seg[now] = pii(arr[l],l);
			return;
		}
		build(ls,l,mid);
		build(rs,mid+1,r);
		seg[now] = max(seg[ls],seg[rs]);
	}
	pii getbig(int now,int l,int r,int s,int e){
		if(l>=s&&e>=r)return seg[now];
		if(mid>=e)return getbig(ls,l,mid,s,e);
		else if(mid<s)return getbig(rs,mid+1,r,s,e);
		else return max(getbig(ls,l,mid,s,e),getbig(rs,mid+1,r,s,e));
	}
#undef ls
#undef rs
#undef mid

	int ans = 0;
	ll pref[mxn];
	set<int> fail;
	set<int> st;
	vector<pii> v;
	void solve(){
		for(int i = 1;i<=N;i++)pref[i] = pref[i-1]+arr[i];
		arr[0] = arr[N+1] = 1e18;
		for(int i = 1;i<=N;i++)v.push_back(pii(arr[i],i));
		sort(v.rbegin(),v.rend());
		st.insert(v[0].sc);
		st.insert(0);
		st.insert(N+1);
		int ans = 1;
		for(int i = 1;i<N;i++){
			auto now = v[i].sc;
			if(fail.find(now) != fail.end())continue;
			auto lit = --st.lower_bound(now);
			auto rit = st.lower_bound(now);
			int s = *lit+1,e = *rit-1;
			if(pref[e]-pref[s-1]>=min(arr[*lit],arr[*rit])){
				ans++;
				st.insert(now);
			}
			else{
				for(int i = s;i<=e;i++)fail.insert(i);
			}
		}
		cout<<ans<<'\n';
		return;
	}
}

namespace S3{
	bitset<mxn> ban;
	ll pref[mxn];
	deque<int> dq;
	pii ch[mxn];
	int dfs(int now,int l,int r){
		if(!now)return 0;
		//cerr<<now<<":"<<l<<','<<r<<','<<ch[now].fs<<' '<<ch[now].sc<<endl;
		int re = 1;
		if(l != now&&pref[now-1]-pref[l-1]>=arr[now])re += dfs(ch[now].fs,l,now-1);
		if(r != now&&pref[r]-pref[now]>=arr[now])re += dfs(ch[now].sc,now+1,r);
		return re;
	}
	int calc(int l,int r){
		dq.clear();
		for(int i = l;i<=r;i++)ch[i].fs = ch[i].sc = 0;
		for(int i = l;i<=r;i++){
			while(!dq.empty()&&arr[dq.back()]<=arr[i]){
				ch[i].fs = dq.back();
				dq.pop_back();
			}
			if(!dq.empty())ch[dq.back()].sc = i;
			dq.push_back(i);
		}
		int ans = dfs(dq[0],l,r);
		return ans;
	}
	void solve(){
		for(int i = 1;i<=N;i++){
			pref[i] = pref[i-1]+arr[i];
		}
		while(Q--){
			int t,l,r;
			cin>>t>>l>>r;
			if(t == 1){
				arr[l] = r;
				for(int i = l;i<=N;i++)pref[i] = pref[i-1]+arr[i];
				continue;
			}
			cout<<calc(l,r)<<'\n';
		}
		return;
	}
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N;
	for(int i = 1;i<=N;i++)cin>>arr[i];
	cin>>Q;
	if(N<=500&&Q<=500)S1::solve();
	else if(Q<=1000)S3::solve();
	else S2::solve();
}

Compilation message (stderr)

fish2.cpp: In function 'int S1::calc(std::vector<int>&)':
fish2.cpp:19:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |   for(int i = 0;i<v.size();i++){
      |                 ~^~~~~~~~~
fish2.cpp:22:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |    while((l>0&&sum>=v[l-1])||(r+1<v.size()&&sum>=v[r+1])){
      |                               ~~~^~~~~~~~~
fish2.cpp:32:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |    if(l == 0&&r+1 == v.size())ans++;
      |               ~~~~^~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 12 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17