Golden October online programming Competition No. 1: Little Girl count

Golden October online programming competition first question: Little Girl count questions details:

[Golden October online programming Competition Rules]

A little girl is counting from 1 to n with her left hand fingers. She starts counting from the thumb as 1. Then, the index finger is 2, the middle finger is 3, the ring finger is 4, and the small finger is 5. Next, adjust the direction. The ring finger is counted as 6, the middle finger is 7, the index finger is 8, and the thumb is 9. Which finger will be parked at the end of the question? The numbers 1, 2, 3, 4, and 5 represent the thumb, index finger, middle finger, ring finger, and small finger in sequence.

Input Format:

Enter multiple groups of data. Each group of data occupies one row and contains only one integer N (1 <=n <= 1000000000 ).

Output Format:

Each group of data occupies one row and only contains an integer between 1 and 5, indicating the last stop finger.

Q & A description:

Input example:

1

10

1000000000

Output example:

1

2

2

Solution: Let's first observe

1 2 3 45

9 87 6

10 11 1213

17 16 15 14

18 19 20 21

25 24 23 22

...

We find that the maximum value of row N is 5 + 4 * (n-1). When n is an even number, the maximum value is at the rightmost, n is at the odd number, and the maximum value is at the leftmost, so we only need to find the given number A in the row, and then reduce it from this maximum value to a to see where it is;

#include <iostream>using namespace std;int main(){    long long n;    while (cin>>n){        double k=(n-5)*1.0/4+1;        double s=k-(int)k;        long long num=k;        if (s)            num++;        long long a=5+4*(num-1);        int answer=0;        if (a>n)            answer=a-n;        else            answer=n-a;        if (num%2==0)            answer+=1;        else            answer=5-answer;        cout<<answer<<endl;    }    return 0;}        

Golden October online programming Competition No. 1: Little Girl count