给定电路图的矩阵表现形式，含有各个支路的连接点及支路导纳。

程序中需要注意电压基准点的处理。当选定基准点后，如果其不是最后一个节点，则节点导纳阵中其后的节点对应的位置值在查找时应该减1。

主程序主要是存储元素，然后显示存储结果，其次选择要查找的元素，输入非法则重新查找，否则正确查找并输出，最后选择是否继续查找，需要则进行前一步，否则程序结束。

存储对角元素就是将含某个行号的值累加赋给相应的DJ数组对角元即可。

存储非对角元素，从第一行开始存储，先遍历电路的矩阵表示形式，对含有节点1的支路导纳负值进行存储，相应行的非零元个数加1，另一个较大的作为列号，存储过的行在电路矩阵中清零，而后进行第二行的存储，依次类推，直至存储完所有的行即可。

查找元素，判断是否为对角元，是则从DJ数组中输出；不是则计算其前面所有行的非零元的个数，从此之后的FD数组中，遍历其后的此行非零元的个数个数，从中查找是否有要找的值，有则输出，没有则说明对应元素的值应该是0。-Given pattern matrix forms, containing various branches of the connection point and branch admittance. The program needs to pay attention to handling the voltage reference point. When you have selected the reference point, if it is not the last node, the node admittance matrix in the subsequent position value corresponding node should be cut when looking for a. Main program storage element, and then store the result is displayed, followed by the elements you want to find, then re-enter the illegal search, find and otherwise correct output, the final choice of whether to continue the search, you need to make before you step in. Otherwise, the program ends. Storage diagonal element is the line number containing a cumulative value assigned to the corresponding diagonal element of the array to DJ. Stored off-diagonal elements,　the first line storage, first traverse the circuit matrix representation of the branch guide contains negative node 1 is satisfied for storage, the corresponding li