对数简化器 - 即时逐步解决方案

1function simplifyLogarithm(expression) {
2  // 处理数值情况
3  if (expression === "log(10)") return "1";
4  if (expression === "log(100)") return "2";
5  if (expression === "log(1000)") return "3";
6  if (expression === "ln(1)") return "0";
7  if (expression === "ln(e)") return "1";
8  
9  // 处理 ln(e^n)
10  const lnExpMatch = expression.match(/ln\(e\^(\w+)\)/);
11  if (lnExpMatch) {
12    return lnExpMatch[1];
13  }
14  
15  // 处理乘积规则：log(x*y)
16  const productMatch = expression.match(/log\((\w+)\*(\w+)\)/);
17  if (productMatch) {
18    const [_, x, y] = productMatch;
19    return `log(${x}) + log(${y})`;
20  }
21  
22  // 处理商规则：log(x/y)
23  const quotientMatch = expression.match(/log\((\w+)\/(\w+)\)/);
24  if (quotientMatch) {
25    const [_, x, y] = quotientMatch;
26    return `log(${x}) - log(${y})`;
27  }
28  
29  // 处理幂规则：log(x^n)
30  const powerMatch = expression.match(/log\((\w+)\^(\w+)\)/);
31  if (powerMatch) {
32    const [_, x, n] = powerMatch;
33    return `${n} * log(${x})`;
34  }
35  
36  // 如果没有简化规则适用，则返回原表达式
37  return expression;
38}
39
40// 使用示例
41const expressions = ["log(10)", "log(x*y)", "log(x/y)", "log(x^3)", "ln(e^5)"];
42expressions.forEach(expr => {
43  console.log(`${expr} → ${simplifyLogarithm(expr)}`);
44});
45

1import java.util.regex.Matcher;
2import java.util.regex.Pattern;
3
4public class LogarithmSimplifier {
5    public static String simplifyLogarithm(String expression) {
6        // 处理数值情况
7        if (expression.equals("log(10)")) return "1";
8        if (expression.equals("log(100)")) return "2";
9        if (expression.equals("log(1000)")) return "3";
10        if (expression.equals("ln(1)")) return "0";
11        if (expression.equals("ln(e)")) return "1";
12        
13        // 处理 ln(e^n)
14        Pattern lnExpPattern = Pattern.compile("ln\\(e\\^(\\w+)\\)");
15        Matcher lnExpMatcher = lnExpPattern.matcher(expression);
16        if (lnExpMatcher.matches()) {
17            return lnExpMatcher.group(1);
18        }
19        
20        // 处理乘积规则：log(x*y)
21        Pattern productPattern = Pattern.compile("log\\((\\w+)\\*(\\w+)\\)");
22        Matcher productMatcher = productPattern.matcher(expression);
23        if (productMatcher.matches()) {
24            String x = productMatcher.group(1);
25            String y = productMatcher.group(2);
26            return "log(" + x + ") + log(" + y + ")";
27        }
28        
29        // 处理商规则：log(x/y)
30        Pattern quotientPattern = Pattern.compile("log\\((\\w+)/(\\w+)\\)");
31        Matcher quotientMatcher = quotientPattern.matcher(expression);
32        if (quotientMatcher.matches()) {
33            String x = quotientMatcher.group(1);
34            String y = quotientMatcher.group(2);
35            return "log(" + x + ") - log(" + y + ")";
36        }
37        
38        // 处理幂规则：log(x^n)
39        Pattern powerPattern = Pattern.compile("log\\((\\w+)\\^(\\w+)\\)");
40        Matcher powerMatcher = powerPattern.matcher(expression);
41        if (powerMatcher.matches()) {
42            String x = powerMatcher.group(1);
43            String n = powerMatcher.group(2);
44            return n + " * log(" + x + ")";
45        }
46        
47        // 如果没有简化规则适用，则返回原表达式
48        return expression;
49    }
50    
51    public static void main(String[] args) {
52        String[] expressions = {"log(10)", "log(x*y)", "log(x/y)", "log(x^3)", "ln(e^5)"};
53        for (String expr : expressions) {
54            System.out.println(expr + " → " + simplifyLogarithm(expr));
55        }
56    }
57}
58

1#include <iostream>
2#include <string>
3#include <regex>
4
5std::string simplifyLogarithm(const std::string& expression) {
6    // 处理数值情况
7    if (expression == "log(10)") return "1";
8    if (expression == "log(100)") return "2";
9    if (expression == "log(1000)") return "3";
10    if (expression == "ln(1)") return "0";
11    if (expression == "ln(e)") return "1";
12    
13    // 处理 ln(e^n)
14    std::regex lnExpPattern("ln\\(e\\^(\\w+)\\)");
15    std::smatch lnExpMatch;
16    if (std::regex_match(expression, lnExpMatch, lnExpPattern)) {
17        return lnExpMatch[1].str();
18    }
19    
20    // 处理乘积规则：log(x*y)
21    std::regex productPattern("log\\((\\w+)\\*(\\w+)\\)");
22    std::smatch productMatch;
23    if (std::regex_match(expression, productMatch, productPattern)) {
24        return "log(" + productMatch[1].str() + ") + log(" + productMatch[2].str() + ")";
25    }
26    
27    // 处理商规则：log(x/y)
28    std::regex quotientPattern("log\\((\\w+)/(\\w+)\\)");
29    std::smatch quotientMatch;
30    if (std::regex_match(expression, quotientMatch, quotientPattern)) {
31        return "log(" + quotientMatch[1].str() + ") - log(" + quotientMatch[2].str() + ")";
32    }
33    
34    // 处理幂规则：log(x^n)
35    std::regex powerPattern("log\\((\\w+)\\^(\\w+)\\)");
36    std::smatch powerMatch;
37    if (std::regex_match(expression, powerMatch, powerPattern)) {
38        return powerMatch[2].str() + " * log(" + powerMatch[1].str() + ")";
39    }
40    
41    // 如果没有简化规则适用，则返回原表达式
42    return expression;
43}
44
45int main() {
46    std::string expressions[] = {"log(10)", "log(x*y)", "log(x/y)", "log(x^3)", "ln(e^5)"};
47    for (const auto& expr : expressions) {
48        std::cout << expr << " → " << simplifyLogarithm(expr) << std::endl;
49    }
50    return 0;
51}
52

1' Excel VBA 对数简化函数
2Function SimplifyLogarithm(expression As String) As String
3    ' 处理数值情况
4    If expression = "log(10)" Then
5        SimplifyLogarithm = "1"
6    ElseIf expression = "log(100)" Then
7        SimplifyLogarithm = "2"
8    ElseIf expression = "log(1000)" Then
9        SimplifyLogarithm = "3"
10    ElseIf expression = "ln(1)" Then
11        SimplifyLogarithm = "0"
12    ElseIf expression = "ln(e)" Then
13        SimplifyLogarithm = "1"
14    ' 处理 ln(e^n) - VBA 中简化的正则表达式
15    ElseIf Left(expression, 5) = "ln(e^" And Right(expression, 1) = ")" Then
16        SimplifyLogarithm = Mid(expression, 6, Len(expression) - 6)
17    ' 对于其他情况，我们需要更复杂的字符串解析
18    ' 这是一个用于演示的简化版本
19    Else
20        SimplifyLogarithm = "使用应用程序处理复杂表达式"
21    End If
22End Function
23