Given a matrix of M x N elements (M rows, N columns), return all elements of the matrix in diagonal order as shown in the below image.
Example:
Input:
[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
]
Output: [1,2,4,7,5,3,6,8,9]
Explanation:
Note:
The total number of elements of the given matrix will not exceed 10,000.
Solution:
1
2
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| class Solution {
public int[] findDiagonalOrder(int[][] A) {
if (A == null || A.length == 0) {
return new int[]{};
}
int rows = A.length;
int cols = A[0].length;
int[] list = new int[rows * cols];
int row = 0;
int col = 0;
int direction = 1;
for (int i = 0; i < list.length; i++) {
list[i] = A[row][col];
if (direction == 1) {
if (col == cols - 1) {
direction = -1;
row++;
} else if (row == 0) {
col++;
direction = -1;
} else {
row--;
col++;
}
} else {
if (row == rows - 1) {
col++;
direction = 1;
} else if (col == 0) {
row++;
direction = 1;
} else {
row++;
col--;
}
}
}
return list;
}
}
|