c语言 square,C语言 螺旋方阵解析（C language spiral square analysis）.doc

C语言 螺旋方阵解析(C language spiral square analysis)

C语言 螺旋方阵解析(C language spiral square analysis)

Three spiral square

Title: Input Height N, printf such pattern:

1, 2, 3, 4, 5

16, 17, 17, 18, 19, 6

15, 24, 25, 20, 7

14 23 22 21 8

13, 12, 11, 10, 9

The first solution is to use an arithmetic sequence to solve this problem.

Algorithm:

1, 2, 3, 4, 5

16, 17, 18, 19, 6

15, 24, 25, 20, 7

14 23 22 21 8

13, 12, 11, 10, 9

Define row I column j. It's stratified from the outside, one layer at a time. Definition r: (r BBB 0 = 1) the current loop is the first lap.

Definition N: graphic height

Definition l: current loop length l

L (1) = N - 1

L (r) = N - 2 * (r - 1) - 1

Set the top left corner of the current loop to start. Definition d: current row direction (top 0 on the right side of 1 and 2 to the left is 3)

Definition pl: current loop length (direction to small number)

Definition a: how many digits are there in the current loop

A (r) = l (r) = 4 * 4 * 2 * (N - (r - 1))

Tolerance for eight

Sum from the outermost circle to the current loop: s (r) = a (1) * r-r * (r - 1) / 2 * (-8)

Definition b: the first number in this circle

B (r) = s (r - 1) + 1

= a (1) * (r - 1) - (r - 1) * (r - 2) / 2 * (8) + 1

Start calculation:

R: r = min (I, N - j + 1, N - I + 1, j)

D: d is (I, N - j + 1, N - I + 1, j) corresponds to r, if r is the first value, then d is the first value...

Pl: p = (j - r, I - r, N - j + 1 - r, N - I + 1 - r) and r correspondence, such as r, such as the first value, it is the first value d...

Current value b + l * d + pl

Commented by Wang Rui

The program is as follows:

The main ()

{int I, j, r, l, b, d, pl, N.

Printf (" Input Height: "); / * input height * /

The scanf (" % d ", & N);

For (I = 1; I < = N i++)

{for (j = 1; j < = N; j + +) / * locates to row I, j column * /

{r = I; D = 0; Pl = j - r;

If (r > N - j + 1) {r = N - j + 1; D = 1; Pl = I - r; }

If (r > N - I + 1) {r = N - (I) + 1; D = 2; Pl = N - j + 1 - r; }

If (r > j) {r = j; D = 3; Pl = N - I + 1 - r; }

/ * find out the number of loops, side position, side positi