问题 A: Elevator

题目描述

The highest building in our city has onlyone elevator. A request list is made up with N positive numbers. The numbersdenote at which floors the elevator will stop, in specified order. It costs 6seconds to move the elevator up one floor, and 4 seconds to move down onefloor. The elevator will stay for 5 seconds at each stop. 

For a given request list, you are to compute the total time spent to fulfillthe requests on the list. The elevator is on the 0th floor at the beginning anddoes not have to return to the ground floor when the requests are fulfilled. 

 

输入

There are multiple test cases. Each casecontains a positive integer N, followed by N positive numbers. All the numbersin the input are less than 100. A test case with N = 0 denotes the end of input.This test case is not to be processed. 

 

输出

Print the total time on a single line foreach test case. 

 

样例输入

1 2

3 2 3 1

0

样例输出

17

41

c:

#include<stdio.h>
int main()
{
	int a,i,n,t,b;
	while(scanf("%d",&n)&&n!=0)
	{	b=0;t=0;
		for(i=1;i<=n;i++)
		{
			scanf("%d",&a);
			if(a>b)
				t=t+6*(a-b);	
			 else if(a<b)
			 	t=t+4*(b-a);
			b=a;t=t+5;	 	
		}
		printf("%d\n",t);
 	 }	
	return 0;
 }