如果数组为 null,访问 length 会抛出 NullPointerException。 java int[] nullArray = null; int len = nullArray.length; // 抛出 NullPointerException 5. 完整示例代码 java public class ArrayLengthExample { public static void main(String[] args) { // 一维数组 int[] numbers = {1, 2, 3, 4,...
21at java.util.concurrent.FutureTask.run(FutureTask.java:266) 22at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) 23at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) 24at java.lang.Thread.run(Thread.java:748) 25java.lang.NullPointerEx...
public class Print2DArray { public static void main(String[] args) { final int[][] matrix = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }; for (int i = 0; i < matrix.length; i++) { //this equals to the row in our matrix. for (int j = 0; j < matrix[i]...
AI代码解释 java.lang.NullPointerException at java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1011)at java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:1006)at com.tencent.matrix.trace.MethodCollector$TraceClassAdapter.visit(MethodCollector.java:284)at org.objectweb.asm...
else {os = new FileOutputStream(output);}os.write(classWriter.toByteArray());os.close();} else {// 这里 对文件进行操作,当 classFile 和 changedFileOutput 路径相同时,导致 `classes.jar` 为 0FileUtil.copyFileUsingStream(classFile, changedFileOutput);}} catch (Exception e) {Log.e(TAG, ...
In order to represent a graph in Java using an incidence matrix, a data structure containing the relationships between vertices and edges must be built. The incidence matrix is a 2D array where the rows and columns stand in for the vertices and edges, respectively, and the entries represent ...
coo_matrix元素访问 coo_matrix的存储方式比较特殊,无法直接访问其中的元素,需要转成csc_matrix...:coo_matrixcoo_matrix是以COOrdinate格式保存矩阵的一种数据结构,官方文档如下: 它可以将array或者list结构转成稀疏矩阵存储: coo_matrix中的 SciPy教程 - 稀疏矩阵库scipy.sparse ...
Use setDeparturePositions(java.util.Collection) or withDeparturePositions(java.util.Collection) if you want to override the existing values. Parameters: departurePositions - The list of departure (origin) positions for the route matrix. An array of points, each of which is it...
at com.tencent.matrix.trace.MethodCollector$CollectJarTask.run(MethodCollector.java:171) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149...
Given n and m which are the dimensions of a matrix initialized by zeros and given an array indices where indices[i] = [ri, ci]. For each pair of [ri, ci] you have to increment all cells in row ri and column ci by 1. Return the number of cells with odd values in the matrix ...