Submission #378343

#	Time	Username	Problem	Language	Result	Execution time	Memory
378343		astoria	Snowball (JOI21_ho_t2)	C++14	33 / 100	33 ms	5284 KiB

Main

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

#define int long long
const int N=1e5+5,Q=1e5+5;
int n,q,x[N];
int pl[Q],pr[Q];
int reachL[N],reachR[N];

int32_t main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);
	cin>>n>>q;
	x[0]=-1e18-5e17; x[n+1]=1e18+5e17;
	for(int i=1; i<=n; i++) cin>>x[i];
	vector<int> seg;
	for(int i=0; i<=n; i++) seg.push_back(x[i+1]-x[i]);
	
	pl[0]=0; pr[0]=0; int po=0;
	for(int i=1; i<=q; i++){
		int v; cin>>v;
		po += v;
		pl[i]=min(pl[i-1],po);
		pr[i]=max(pr[i-1],po);
	}
	pl[q+1]=-4e18; pr[q+1]=4e18;
	
	reachL[1]=pl[q]; reachR[n]=pr[q];
	
	for(int lo=2; lo<=q; lo++){
		assert(pl[lo]==pl[lo-1] || pr[lo]==pr[lo-1]);
	}
	
	for(int i=1; i<n; i++){
		int len = seg[i];
		int lo=0,hi=q+1; //first pos where pl+pr >= len
		while(lo<hi){
			int mid=(lo+hi)>>1;
			if(pr[mid]-pl[mid] >= len) hi=mid;
			else lo=mid+1;
		}
		//cout<<lo<<endl;
		if(lo==q+1){
			reachR[i]=pr[q];
			reachL[i+1]=pl[q];
			continue;
		} //case where they never meet
		assert(lo!=0); //len is positive
		assert(pl[lo]==pl[lo-1] || pr[lo]==pr[lo-1] || lo==q+1); //this statement is triggered. How? Oh, Q+1 so not really
		//assert(pl[lo]!=pl[lo-1] || pr[lo]!=pr[lo-1]);
		
		if(pl[lo]!=pl[lo-1]){
			reachR[i] = pr[lo-1];
			reachL[i+1] = - (len - pr[lo-1]); //note reachL is negative
			//cout<<"LEFTCAUSE"<<i<<endl;
		} //left caused the ending
		else{
			reachL[i+1] = pl[lo-1];
			reachR[i] = len + pl[lo-1]; //reachL is negative so it's subtraction
			//cout<<"RIGHTCAUSE"<<i<<endl;
		} //right caused the ending
	}
	for(int i=1; i<=n; i++){
		cout<<reachR[i]-reachL[i]<<'\n';
	}
	
	/*for(int i=0; i<=q+1; i++){
		cout<<pl[i]<<" "<<pr[i]<<endl;
	}*/
}

• Subtask 1: 33 / 33
• Subtask 2: 0 / 67