PROBLEM DESCRIPTION
You are given a rectangular matrix, and your task is to return an array while traversing the matrix in spiral form.
SOLUTION
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class Solution {
// Function to return a list of integers denoting spiral traversal of matrix.
public ArrayList<Integer> spirallyTraverse(int matrix[][]) {
int n = matrix.length;
int m = matrix[0].length;
int topRow = 0;
int bottomRow = n-1;
int leftColumn = 0;
int rightColumn = m-1;
ArrayList<Integer> list = new ArrayList<>();
while(topRow <= bottomRow && leftColumn <= rightColumn){
// top
for(int c=leftColumn; c<=rightColumn; c++){
list.add(matrix[topRow][c]);
}
// right
for(int r=topRow+1; r<=bottomRow; r++){
list.add(matrix[r][rightColumn]);
}
// bottom
for(int c=rightColumn-1; c>=leftColumn; c--){
if(topRow == bottomRow) break;
list.add(matrix[bottomRow][c]);
}
// left
for(int r=bottomRow-1; r>=topRow+1; r--){
if(leftColumn == rightColumn) break;
list.add(matrix[r][leftColumn]);
}
topRow++;
bottomRow--;
leftColumn++;
rightColumn--;
}
return list;
}
}