Function and Function（青岛icpc）

滴答滴答---题目链接 

Function and Function

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Time Limit: 1 Second      Memory Limit: 65536 KB

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If we define , do you know what function  means?

Actually,  calculates the total number of enclosed areas produced by each digit in . The following table shows the number of enclosed areas produced by each digit:

Enclosed Area	Digit	Enclosed Area	Digit
0	1	5	0
1	0	6	1
2	0	7	0
3	0	8	2
4	1	9	1

For example, , and .

We now define a recursive function  by the following equations:

For example, , and .

Given two integers  and , please calculate the value of .

Input

There are multiple test cases. The first line of the input contains an integer  (about ), indicating the number of test cases. For each test case:

The first and only line contains two integers  and  (). Positive integers are given without leading zeros, and zero is given with exactly one '0'.

Output

For each test case output one line containing one integer, indicating the value of .

Sample Input

6
123456789 1
888888888 1
888888888 2
888888888 999999999
98640 12345
1000000000 0

Sample Output

5
18
2
0
0
1000000000

Hint

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Author: WENG, Caizhi
Source: The 2018 ACM-ICPC Asia Qingdao Regional Contest

Submit    Status

#include <iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int a[10]= {1,0,0,0,1,0,1,0,2,1};
int ff(long long n)
{

    int sum=0;
    if(n==0)
        return 0;
    while(n>0)
    {
        sum+=a[n%10];
        n/=10;
    }
    return sum;
}
long long f(long long n,long long k,long long m)
{
    int a;
    if(k==0)
        return n;
    a=ff(n);
    if(n==0)
    {
        if(k%2)
            return 1;
        else return 0;
    }
    if(n==1)
    {
        if(k%2)
            return 0;
        else return 1;
    }
    return f(a,k-1,m);
}
int main()
{
    long long t,k,n;
    scanf("%lld",&t);
    while(t--)
    {
        scanf("%lld%lld",&n,&k);
        printf("%lld\n",f(n,k,k));
    }
    return 0;
}