A mathematical question, look for patterns.
First, you must determine the number at the nth layer, for example, at the nth layer. Then, judge the relationship between (N * n-n + 1) (its coordinates are (n, n.
Pay attention to the parity of N.
Problem A. Ant on a chessboard |
Background
One day, an ant called Alice came to an M * m chessboard. she wanted to go around all the grids. so she began to walk along the chessboard according to this way: (you can assume that her speed is one grid per second)
At the first second, Alice was standing at (1, 1 ). firstly she went up for a grid, then a grid to the right, a grid downward. after that, she went a grid to the right, then two grids upward, and then two grids to the left... In a word, the path was like a snake.
For example, her first 25 seconds went like this:
(The numbers in the grids stands for the time when she went into the grids)
25 |
24 |
23 |
22 |
21 |
10 |
11 |
12 |
13 |
20 |
9 |
8 |
7 |
14 |
19 |
2 |
3 |
6 |
15 |
18 |
1 |
4 |
5 |
16 |
17 |
5
4
3
2
1
1 2 3 4 5
At the 8th second, she was at (2, 3), and at 20th second, she was at (5, 4 ).
Your task is to decide where she was at a given time.
(You can assume that M is large enough)
Input
Input file will contain several lines, and each line contains a number N (1 <= n <= 2*10 ^ 9), which stands for the time. the file will be ended with a line that contains a number 0.
Output
For each input situation you shocould print a line with two numbers (x, y), the column and the row number, there must be only a space between them.
Sample Input
8
20
25
0
Sample output
2 3
5 4
1 5
AC code:
1 //#define LOCAL 2 #include <iostream> 3 #include <cstdio> 4 #include <cstring> 5 #include <cmath> 6 using namespace std; 7 8 int main(void) 9 {10 #ifdef LOCAL11 freopen("10161in.txt", "r", stdin);12 #endif13 14 int N;15 while(scanf("%d", &N) == 1 && N)16 {17 int n = (int)ceil(sqrt(N));18 int x, y;19 if(n & 1 == 1)20 {21 if(N < n * n - n + 1)22 {23 x = n;24 y = N - (n - 1) * (n - 1);25 }26 else27 {28 y = n;29 x = n * n - N + 1;30 }31 }32 else33 {34 if(N < n * n - n + 1)35 {36 y = n;37 x = N - (n - 1) * (n - 1);38 }39 else40 {41 x = n;42 y = n * n - N + 1;43 }44 }45 46 cout << x << " " << y << endl;47 }48 return 0;49 }
Code Jun