Submission #40997506

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define op(x) ((x&1)?x+1:x-1)
#define odd(x) (x&1)
#define even(x) (!odd(x))
#define lc(x) (x<<1)
#define rc(x) (lc(x)|1)
#define lowbit(x) (x&-x)
#define mp(x,y) make_pair(x,y)
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
using namespace std;
const ll MAXN=3e5+10;

ll n,T;
ll x[MAXN],t[MAXN],L[MAXN],R[MAXN];
int vis[MAXN];

stack<int>st;

ll ans;

int main(){

	cin>>n>>T;
	rep(i,1,n)cin>>x[i];
	rep(i,1,n)cin>>t[i];

	rep(i,1,n){
		ans += (t[i])/(T<<1);
		t[i] %= (T<<1);
		if(t[i]==0){
			ans--;
			continue;
		}
 
		L[i] = (2*(T-x[i]) >= t[i]) ? (1) : (0);
		R[i] = (2*x[i] >= t[i]) ? (1) : (0);
	}

	ans+=n+(!L[n]);

	rep(i,1,n-1){
		if(L[i] && R[i])st.push(i);
		else if(L[i] && !R[i]){
			if(st.size()){
				ans--;
				vis[st.top()]=1;
				st.pop();
			}
		}
	}
	while(st.size())st.pop();
	per(i,n-1,1){
		if(L[i] && R[i])st.push(i);
		else if(!L[i] && R[i]){
			if(st.size()){
				ans--;
				vis[st.top()]=1;
				st.pop();
			}
		}
	}
	int cnt=0;
	rep(i,1,n-1)if(L[i] && R[i] && !vis[i])cnt++;

	ans-=(cnt/2);

	ans*=(2*T);
	cout<<ans<<endl;

    return 0;
}

Submission Info

Judge Result