有一3×3的矩阵，用下标法编程实现：（1）二维数据组元素的输入和输出；（2）求每行元素的和值，存入一个一维数组并输出-There is a 3* 3 matrix, with subscr ipt method programming: (1) the two-dimensional data set of elements in the input and output　(2) for each element and the value, stored in a one-dimensional array and output