loop

loop.cpp

#include <stdio.h>

#define ROW 	5
#define COLUMN 	(ROW + 1)

static unsigned ix;
static unsigned iy;
static unsigned ctr = 1;
static unsigned sta = 0;

static int arr[ROW][COLUMN];
static int *ptr_arr[ROW];
static int len[ROW];

void shuffle(int row) {
	unsigned num = 1;
	for (iy = 0; iy < row; iy++) {
		num = num*len[iy];
	}

	if (sta % num == 0) {
		ptr_arr[row] ++;
		if (*ptr_arr[row] == 0)
			ptr_arr[row] = &arr[row][0];
	}
}

void print_out() {
	sta ++ ;
	printf("[%d/%d]\t", sta, ctr);

	for (ix = 0; ix < ROW; ix++) {
		printf("%d\t", *ptr_arr[ix]);
	}
	printf("\n");

	for (ix = 0; ix < ROW; ix++) {
		shuffle(ix);
	}
}

int main(int argc, char const *argv[]) {
	/*initialize array, each line end with 0.*/
	printf("\ninitialize a int type array.\n");
	for (ix = 0; ix < ROW; ix ++) {
		for (iy = 0; iy < COLUMN; iy ++) {
			arr[ix][iy] = iy + ix*10 + 1;
		}
		arr[ix][COLUMN - 1] = 0;
	}
	for (ix = 0; ix < ROW; ix ++) {
		for (iy = 0; iy < COLUMN; iy ++)
			printf("%d\t", arr[ix][iy]);
		printf("\n");
	}

	printf("\ninitialize a pointer array to point the first element of each row.\n");
	for (ix = 0; ix < ROW; ix ++) {
		ptr_arr[ix] = &arr[ix][0];
		printf("ptr_arr[%d] -> %d\n", ix, *ptr_arr[ix]);
	}
	/*caculate the loop times.*/
	for (ix = 0; ix < ROW; ix++) {
		ctr = ctr*(COLUMN - 1);
	}
	/*get the length of each row.*/
	for (ix = 0; ix < ROW; ix++) {
		len[ix] = COLUMN - 1;
	}
	printf("\ninitialize a pointer array to point the first element of each row.\n");
	for (ix = 0; ix < ROW; ix ++) {
		ptr_arr[ix] = &arr[ix][0];
		printf("ptr_arr[%d] -> %d\n", ix, *ptr_arr[ix]);
	}

	printf("\nprint out result[%d]:\n", ctr);
	while(sta != ctr) {
		print_out();
	}

	return 0;
}