public class Solution {
public ArrayList<Integer> printMatrix(int [][] matrix) {
ArrayList<Integer> list=new ArrayList<Integer>();
int column=matrix[0].length;
int row=matrix.length;
if(column==0||row==0) return list;
//下面设定上下左右边界
int top=0,bottom=row-1;
int left=0,right=column-1;
while(left<=right&&top<=bottom){
for(int i=left;i<=right;i++){
list.add(matrix[top][i]);
}
for(int i=top+1;i<=bottom;i++){
list.add(matrix[i][right]);
}
for(int i=right-1;i>=left&&top<bottom;i--){
list.add(matrix[bottom][i]);
}
for(int i=bottom-1;i>=top+1&&left<right;i--){
list.add(matrix[i][left]);
}
left++;
right--;
top++;
bottom--;
}
return list;
}
}