###### tags: `Zerojudge`
【題解】apcs h081: 1.程式交易
===
Posted on 2022/4/28 | By : Victoria1103
【題目敘述】https://zerojudge.tw/ShowProblem?problemid=h081

#include <iostream>
using namespace std;

int main ()
{
	int n , D ;
	cin >> n >> D ;
	int a[n] ;
	for (int i = 0 ; i < n ; i++ ) 
	{
		cin >> a[i] ;
	}
	int have = 1 , x = a[0] , y = 0 ;//持有股票
	int ans = 0 ;
	for (int i = 1; i < n ; i++)
	{
		if (have==1 && a[i]-x>=D){
			y = a[i];
            ans += y-x;//利潤 
            have=0;
        }
		else if(have==0 && y-a[i]>=D){
            x = a[i];
            have=1;
        }
	
	}
	cout << ans ;
	return 0;
}