One-Based Arithmetic
time limit per test
0.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Prof. Vasechkin wants to represent positive integer n as a sum of addends, where each addends is an integer number containing only
1s. For example, he can represent 121 as 121=111+11+–1. Help him to find the least number of digits
1 in such sum.
Input
The first line of the input contains integer n (1 ≤ n < 1015).
Output
Print expected minimal number of digits 1.
Sample test(s)
Input
121
Output
6
思路:一个数能够从比他大的数减,也能够从比它小的数的倍数加。
import java.util.*;
public class Main {
static long ones[]=new long[17];
static long dfs(long n,int i){
int k=(int) (n/ones[i]);
n%=ones[i];
long count=k*i;
if(n==0) return count;
else
return count+Math.min(i+dfs(ones[i]-n,i-1),dfs(n,i-1));
}
public static void main(String[] args) {
Scanner scan=new Scanner(System.in);
long n=scan.nextLong();
ones[0]=0;
for(int i=1;i<=16;i++){
ones[i]=ones[i-1]*10+1;
}
System.out.println(dfs(n,16));
} }