2013
11-12

# Ecology tax

In a big and rich on natural resources country, the government started a campaign to control deforestation. In fact the government is not too interested in how many trees get fallen, but rather how effectively the wood is utilized. So a law was passed which requires every logging company to pay amount of money in proportion to amount of wood that it wastes during operation.

A felling quota on some territory was allotted to a company in this country. Company lorries may only transport logs of exactly L meters long. So when a tree gets sawed into logs, the remainder is wasted.

Trees in this country grow exactly 1 meter per year, so the company may decrease the amount of tax to be paid by simply waiting for some years. Your task is to determine the number of years needed to achieve smallest possible tax. If there is more than one answer, find minimal (earliest) one.

Input file contains number of trees N, length of log L, followed by integers i1 i2iN — heights of each tree.

#### Constraints

1 ≤ N ≤ 30000, 1 ≤ L, ik ≤ 30000

Output file must contain single integer — number of years to wait.

Sample Input 1
3 1
10 15 11
Sample Input 2
3 2
5 3 6

Sample Output 1
0
Sample Output 2
1

Bold texts appearing in the sample sections are informative and do not form part of the actual data.

/* @author: */
import java.util.Scanner;
import java.util.Arrays;
public class Main{

public static void main(String args[])
{
Scanner sc=new Scanner(System.in);
int n,L,v;
n=sc.nextInt();
L=sc.nextInt();
int m=0;
while((n--)!=0)
{
v=sc.nextInt();
if(v%L==0)continue;
int u=L-v%L;
if(u>m)m=u;
}
System.out.printf("%d",m);
}
}

1. 这道题目虽然简单，但是小编做的很到位，应该会给很多人启发吧！对于面试当中不给开辟额外空间的问题不是绝对的，实际上至少是允许少数变量存在的。之前遇到相似的问题也是恍然大悟，今天看到小编这篇文章相见恨晚。