*               y
 *         0     1     2			    (y,t)
 *		+-----+-----+-----+            +-----+
 *	  0	|(0,0)|(0,1)|(0,2)|            |(0,0)| 0 = 0*3+0 = t*3+y
 *		+-----+-----+-----+            +-----+
 * t  1	|(1,0)|(1,1)|(1,2)|            |(0,1)| 1 = 0*3+1 = t*3+y
 *		+-----+-----+-----+            +-----+
 *	  2	|(2,0)|(2,1)|(2,2)|            |(0,2)| 2 = 0*3+2 = t*3+y
 *		+-----+-----+-----+            +-----+

 *		+-----+-----+-----+
 *	  0	|  0  |  1  |  2  |
 *		+-----+-----+-----+
 *	t 1	|  3  |  4  |  5  |
 *		+-----+-----+-----+
 *	  2	|  6  |  7  |  8  |
 *		+-----+-----+-----+


char a[3];

	a0,a1,a2

	a  == &a0

	a[n] == *(a + n)

char board[3][3];

	board00,board01,board02,board10,..,board22 の 9 個 ( 3 x 3 )

	board 〜 &board[0][0]

	board[1]
		 board10, board11, board12

	board[1] 〜 &board[1][0]
				sizeof(board[1][0]) == 1		board[1][0] : char
				sizeof(board[1]) == 3			board[1] : char[3]

	board[1][n] == *(board[1] + n)

	board[k] == *( board + k )
			 board には 1000 というアドレスの情報だけでなく
			その要素のサイズの情報も含まれている


	board == 1000
	board[1] => *(1003)
			= *(board + 1)						// ポインター計算
												// ポインター==アドレス値と型情報
			  => *(1000 + 1*sizeof(board[1]))	// アドレス値の計算
			  => *(1000 + 1*3)
			  => *(1003)

	sizeof ( X )
		X がメモリを使うセルの個数


==

fact(5) =>
	n <- 5;
		fact ( n - 1 ) * n
			=> fact ( 5 - 1 ) * 5
				=> fact ( 4 ) * 5

fact(4)	
	n <- 4;
		fact ( n - 1 ) * n
			=> fact ( 4 - 1 ) * 4
				=> fact ( 3 ) * 4
..
fact(0)
	n <- 0
		1
	=> 1
		=> 1 * 2
			=> 1 * 2 * 3
				...
					=> 1 * 2 * 3 * 4 * 5 = 120


==

fact(5)
				n : bf9c8950
	n <- 5
				*(bf9c8950) <- 5
		fcat(n-1) * n
			fcat(4) * n

fact(4)
				n : bf9c8930
	n <- 4
				*(bf9c8930) <- 4
		fcat(n-1) * n
			fcat(4) * n


==

print_int_form ( "1 st = %, 2nd = %, 3rd \n", 10, 20, 90 );

int print_int_form ( char *fmt, int a, ... )

		+-----------+
fmt		|	--------------------> "1 st = %, 2nd = %, 3rd \n"
		+-----------+			+-----+
a		|	10		|*(&a+0)	| '1' |			<- fmt[0] = fmt[i] (i = 0 の時)
		+-----------+	j=0		+-----+
		|    20		|*(&a+1)	| 's' |			<- fmt[1] = fmt[i] (i = 1 の時)
		+-----------+	j=1		+-----+
		|    90		|			| 't' |
		+-----------+			+-----+
								| ..  |
 	


1 st = 10, 2nd = 20, 3rd = 90