这道题找规律 ，如果暴力基本超时了 ，找到规律就好做了 我的方法是把表格看成一层一层的 倒着的L型是一层 然后把层中间的数计算出来 与用户输入的数作差 再判断下奇偶，分情况讨论 算法复杂度虽然说是 O(1)但是 代码感觉还是繁琐了 有空再想想更简单的解法。
笔记：
ceil是向上取整
floor是向下取整
|
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 should 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
1 #include<stdio.h> 2 #include<math.h> 3 4 int main(void) 5 { 6 int n; 7 while (scanf("%d", &n) && n!=0) 8 { 9 int l = ceil((sqrt(1.0*n))); //l指的是这个数所处的层数 10 int lmid= l*l-(l-1); //lmax是这个层的中间那个数 11 int dis = n - lmid; 12 //分情况讨论 13 if (l % 2==0 && dis >= 0) printf("%d %d", l, l - dis); 14 else if (l % 2==0 && dis < 0) printf("%d %d", l + dis, l); 15 else if (l % 2 && dis>=0) printf("%d %d", l - dis, l); 16 else if (l % 2 && dis < 0) printf("%d %d", l, l + dis); 17 printf(" "); 18 } 19 return 0; 20 }