class Solution {
    public int[] printMatrix(int[][] matrix) {
        int row = matrix.length;
        int[] r = new int[0];
        if(row==0)
            return r;
        int col = matrix[0].length;
        if(col==0)
            return r;

        int i=0; int j=0;
        int a=row-1; int b=col-1;
        int[] re = new int[row*col];
        int count=0;

        while(i<=a||j<=b){
            for(int t = j; t <= b; t++)//向右
                if(matrix[i][t]!=Integer.MIN_VALUE){
                    re[count]=matrix[i][t];
                    count++;
                    matrix[i][t]=Integer.MIN_VALUE;
                }

            for(int s = i+1; s <= a; s++)//向下
                if(matrix[s][b]!=Integer.MIN_VALUE){
                    re[count]=matrix[s][b];
                    count++;
                    matrix[s][b]=Integer.MIN_VALUE;
                }

            for(int t = b-1; t>=j; t--)//向左
                if(matrix[a][t]!=Integer.MIN_VALUE){
                    re[count]=matrix[a][t];
                    count++;
                    matrix[a][t]=Integer.MIN_VALUE;
                }

            for(int s = a-1; s>i; s--)//向上
                if(matrix[s][j]!=Integer.MIN_VALUE){
                    re[count]=matrix[s][j];
                    count++;
                    matrix[s][j]=Integer.MIN_VALUE;
                }

            i++;j++;
            a--;b--;
            if(a<0||b<0)
                break;
        }
        return re;
    }
}