题解 | #顺时针打印矩阵#

代码如下： 需要注意的是每次打印后判断边界的情况。 public static ArrayList printMatrix1(int [][] matrix) { int left = 0; int right = matrix[0].length-1; int top = 0; int bottom = matrix.length-1;

    ArrayList arrayList = new ArrayList();

    while (true){
        //->
        for (int i = left; i < right+1; i++) {
            arrayList.add(matrix[top][i]);
        }
        top++;
        if( top > bottom ){
            break;
        }
        //向下
        for (int i = top; i < bottom+1; i++) {
            arrayList.add(matrix[i][right]);
        }
        right--;
        if( left > right ){
            break;
        }
        //<-
        for (int i = right; i > left-1; i--) {
            arrayList.add(matrix[bottom][i]);
        }
        bottom--;
        if( top > bottom ){
            break;
        }
        //向上
        for (int i = bottom; i >top-1 ; i--) {
            arrayList.add(matrix[i][left]);
        }
        left++;
        if( left > right ){
            break;
        }
    }

    for (int i = 0; i < arrayList.size(); i++) {
        System.out.println(" "+arrayList.get(i));
    }
    return arrayList;
}