Submission #352377

#	Time	Username	Problem	Language	Result	Execution time	Memory
352377		Kerim	Shortcut (IOI16_shortcut)	C++17	100 / 100	1197 ms	65172 KiB

shortcut

#include "shortcut.h"
#include "bits/stdc++.h"
#define MAXN 1000009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;

typedef long long ll;
typedef pair<ll,ll> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const ll B=1e18;
vector<ll>x;
vector<int>d;
int n,pos;
pair<int,PII>a[MAXN];
ll cost,K;
PII cur[MAXN];
bool ok(ll k){K=k-cost;
	ll A1=-B,A2=B,B1=-B,B2=B;
	PII res=mp(B,-B);
	int p1=0,p2=0;
	for(int i=0;i<n;i++){
		ll dif=x[i]-d[i],sum=x[i]+d[i];
		while(p1<p2 and sum-cur[p1].ff>k){
			umin(res.ff,cur[p1].ff);
			umax(res.ss,x[cur[p1].ss]+d[cur[p1].ss]);
			p1++;	
		}
		umin(A2,dif+res.ff+K);umax(A1,sum+res.ss-K);
		umin(B2,dif-res.ss+K);umax(B1,sum-res.ff-K);
		while(p2>p1 and cur[p2-1].ff>dif)p2--;
		cur[p2++]=mp(dif,i);
	}
	if(A1>A2 or B1>B2)return 0;
	for(int j=0,p=0;j<n;j++){
		ll xx=max(A1-x[j],x[j]-B2),yy=min(A2-x[j],x[j]-B1);
		while(p>0 and x[p-1]>=xx)p--;
		if(p<j and x[p]>=xx and x[p]<=yy)return 1;
		while(p<j and x[p]<xx)p++;
	}
	return 0;
}
long long find_shortcut(int N,vector<int> l,vector<int>D, int c_edge){
	d=D;cost=c_edge;n=N;x.resize(n);for(int i=0;i<n;i++)x[i]=0;
	for(int i=0;i<n-1;i++)x[i+1]=x[i]+l[i];
	ll st=1,en=ll(2e15);
	while(st+1<en){
		ll mid=(st+en)>>1;
		if(ok(mid))en=mid;
		else st=mid;
	}
	if(ok(st))return st;
	return en;
}

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 33 / 33
• Subtask 6: 22 / 22
• Subtask 7: 4 / 4
• Subtask 8: 3 / 3