Java 编程题：字符串转整数 & 冒泡排序实现降序排序

"三.编程题\n1.int parseinteger(String s){\n}\n请用代码实现这个java库的基础方法.\n\n\n2.用冒泡排序法(其他排序方法也行)对数组{9,2,7,6,23}按降序进行排序,并写出最终结果."\n1. 实现parseInteger方法：\n\njava\nint parseInteger(String s) {\n int result = 0;\n boolean isNegative = false;\n int i = 0;\n\n if (s.charAt(0) == '-') {\n isNegative = true;\n i = 1;\n }\n\n for (; i < s.length(); i++) {\n char c = s.charAt(i);\n if (c >= '0' && c <= '9') {\n int digit = c - '0';\n result = result * 10 + digit;\n } else {\n throw new IllegalArgumentException("Invalid input: " + s);\n }\n }\n\n return isNegative ? -result : result;\n}\n\n\n2. 用冒泡排序法对数组按降序进行排序：\n\njava\nint[] arr = {9, 2, 7, 6, 23};\n\nfor (int i = 0; i < arr.length - 1; i++) {\n for (int j = 0; j < arr.length - i - 1; j++) {\n if (arr[j] < arr[j + 1]) {\n int temp = arr[j];\n arr[j] = arr[j + 1];\n arr[j + 1] = temp;\n }\n }\n}\n\nSystem.out.println(Arrays.toString(arr));\n\n\n最终结果：[23, 9, 7, 6, 2]