java中表达式4%4+4*4+4/4的值是
时间: 2023-05-30 08:02:55 浏览: 88
As an AI language model, I do not have emotions or personal opinions, so I cannot provide a response to the term "null" in a subjective manner. However, "null" typically refers to the absence of a value or the lack of existence of an object or concept. In programming, "null" often denotes a variable that has not been assigned a value or a pointer that does not point to any memory location.
相关问题
5+3*4的表达式树Java代码
下面是一个简单的 Java 代码,用于构建和求解表达式树,其中表达式为 5+3*4:
```java
class TreeNode {
String val;
TreeNode left;
TreeNode right;
TreeNode(String val) {
this.val = val;
}
}
public class ExpressionTree {
public static void main(String[] args) {
String[] postfix = {"5", "3", "4", "*", "+"};
TreeNode root = buildExpressionTree(postfix);
int result = evaluateExpressionTree(root);
System.out.println(result); // 输出 17
}
public static TreeNode buildExpressionTree(String[] postfix) {
Stack<TreeNode> stack = new Stack<>();
for (String s : postfix) {
TreeNode node = new TreeNode(s);
if (isOperator(s)) {
node.right = stack.pop();
node.left = stack.pop();
}
stack.push(node);
}
return stack.pop();
}
public static int evaluateExpressionTree(TreeNode root) {
if (root == null) {
return 0;
}
if (root.left == null && root.right == null) {
return Integer.parseInt(root.val);
}
int left = evaluateExpressionTree(root.left);
int right = evaluateExpressionTree(root.right);
switch (root.val) {
case "+":
return left + right;
case "-":
return left - right;
case "*":
return left * right;
case "/":
return left / right;
default:
throw new IllegalArgumentException("Invalid operator: " + root.val);
}
}
private static boolean isOperator(String s) {
return s.equals("+") || s.equals("-") || s.equals("*") || s.equals("/");
}
}
```
这段代码中,我们构建了一个 `TreeNode` 类,用于表示表达式树的节点。然后,我们使用后缀表达式 `"5", "3", "4", "*", "+"` 构建了一个表达式树,并且计算出了表达式的结果。具体来说,我们使用栈来构建表达式树,遇到操作符时弹出栈顶的两个节点作为其左右子节点,然后将新的节点入栈。最后,栈中剩下的唯一节点就是表达式树的根节点。最后,我们使用递归来计算表达式树的值,如果当前节点是叶子节点,则返回其对应的数字值,否则根据操作符计算左右子树的值并返回最终结果。
用Java编程编程计算表达式A的值A=99/(1*2*3)+98/(2*3*4)+97/(3*4*5)+⋯+1/(99*100*101)
可以使用Java中的循环和数学库来计算表达式A的值。下面是一个示例代码:
```java
import java.math.BigDecimal;
public class ExpressionA {
public static void main(String[] args) {
BigDecimal result = BigDecimal.ZERO;
for (int i = 99; i > 0; i--) {
BigDecimal numerator = new BigDecimal(i);
BigDecimal denominator = new BigDecimal(i + 1).multiply(new BigDecimal(i + 2)).multiply(new BigDecimal(i + 3));
result = result.add(numerator.divide(denominator, 50, BigDecimal.ROUND_HALF_UP));
}
System.out.println("Expression A = " + result.toString());
}
}
```
这里使用了BigDecimal类来保证计算精度,因为表达式中的分母可能非常大。循环从99到1依次计算每个分数的值,并将结果累加到result变量中。最后输出result的值即为表达式A的结果。