Print a given matrix in spiral form
Input: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Output: 1 2 3 4 8 12 16 15 14 13 9 5 6 7 11 10 Input: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Output: 1 2 3 4 5 6 12 18 17 16 15 14 13 7 8 9 10 11
Analysis:
void spiralPrint(int m, int n, int a[R][C])
{
int i, k = 0, l = 0;
/* k - starting row index
m - ending row index
l - starting column index
n - ending column index
i - iterator
*/
//while row and column are both still valid
while (k < m && l < n)
{
/* Print the first row from the remaining rows */
for (i = l; i < n; ++i)
{
printf("%d ", a[k][i]);
}
k++;
/* Print the last column from the remaining columns */
for (i = k; i < m; ++i)
{
printf("%d ", a[i][n-1]);
}
n--;
/* Print the last row from the remaining rows */
if ( k < m)
{
for (i = n-1; i >= l; --i)
{
printf("%d ", a[m-1][i]);
}
m--;
}
/* Print the first column from the remaining columns */
if (l < n)
{
for (i = m-1; i >= k; --i)
{
printf("%d ", a[i][l]);
}
l++;
}
}
}
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