LittleSheep/SimpleMathCalc
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♻️ Replaced with own calculator

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This commit is contained in:
LittleSheep
2025-09-14 02:22:27 +08:00
parent 90a77a2cba
commit 3f0bcb472d
4 changed files with 273 additions and 35 deletions
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167
lib/solver.dart
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@@ -1,8 +1,8 @@
import 'dart:math';
import 'package:flutter/foundation.dart'; // For kDebugMode
import 'package:math_expressions/math_expressions.dart';
import 'package:rational/rational.dart';
import 'models/calculation_step.dart';
import 'calculator.dart';
import 'parser.dart';
/// 帮助解析一元一次方程 ax+b=cx+d 的辅助类
class LinearEquationParts {
@@ -43,9 +43,6 @@ class SolverService {
try {
return _solveSimpleExpression(input); // 使用原始输入以保留运算符
} catch (e) {
if (kDebugMode) {
print(e);
}
throw Exception('无法识别的格式。请检查您的方程或表达式。');
}
}
@@ -76,17 +73,41 @@ class SolverService {
// 预处理输入，将三角函数的参数从度转换为弧度
String processedInput = _convertTrigToRadians(input);
GrammarParser p = GrammarParser();
Expression exp = p.parse(processedInput);
final result = RealEvaluator().evaluate(exp).toDouble();
try {
// 使用自定义解析器解析表达式
final parser = Parser(processedInput);
final expr = parser.parse();
// 尝试将结果格式化为几倍根号的形式
final formattedResult = _formatSqrtResult(result);
// 对表达式进行求值
final evaluatedExpr = expr.evaluate();
return CalculationResult(
steps: steps,
finalAnswer: '\$\$$formattedResult\$\$',
);
// 获取数值结果 - 需要正确进行类型转换
double result;
if (evaluatedExpr is IntExpr) {
result = evaluatedExpr.value.toDouble();
} else if (evaluatedExpr is DoubleExpr) {
result = evaluatedExpr.value;
} else if (evaluatedExpr is FractionExpr) {
result = evaluatedExpr.numerator / evaluatedExpr.denominator;
} else {
// 如果无法完全求值为数值，尝试简化并转换为字符串
final simplified = evaluatedExpr.simplify();
return CalculationResult(
steps: steps,
finalAnswer: '\$\$${simplified.toString()}\$\$',
);
}
// 尝试将结果格式化为几倍根号的形式
final formattedResult = _formatSqrtResult(result);
return CalculationResult(
steps: steps,
finalAnswer: '\$\$$formattedResult\$\$',
);
} catch (e) {
throw Exception('无法解析表达式: $input');
}
}
/// 2. 求解一元一次方程
@@ -714,21 +735,28 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
if (factorMulMatch != null) {
final factor1 = factorMulMatch.group(1)!;
final factor2 = factorMulMatch.group(2)!;
print('Expanding: ($factor1) * ($factor2)');
final coeffs1 = _parsePolynomial(factor1);
final coeffs2 = _parsePolynomial(factor2);
print('Coeffs1: $coeffs1, Coeffs2: $coeffs2');
final a = coeffs1[1] ?? 0;
final b = coeffs1[0] ?? 0;
final c = coeffs2[1] ?? 0;
final d = coeffs2[0] ?? 0;
print('a=$a, b=$b, c=$c, d=$d');
final newA = a * c;
final newB = a * d + b * c;
final newC = b * d;
print('newA=$newA, newB=$newB, newC=$newC');
final expanded =
'${newA}x^2${newB >= 0 ? '+' : ''}${newB}x${newC >= 0 ? '+' : ''}$newC';
result = result.replaceFirst(factorMulMatch.group(0)!, '($expanded)');
print('Expanded result: $expanded');
result = result.replaceFirst(factorMulMatch.group(0)!, expanded);
iterationCount++;
continue;
}
@@ -762,7 +790,11 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
final newC = termB * factorB;
final expanded =
'${newA}x^2${newB >= 0 ? '+' : ''}${newB}x${newC >= 0 ? '+' : ''}$newC';
'${newA == 1
? ''
: newA == -1
? '-'
: newA}x^2${newB >= 0 ? '+' : ''}${newB}x${newC >= 0 ? '+' : ''}$newC';
result = result.replaceFirst(termFactorMatch.group(0)!, '($expanded)');
iterationCount++;
continue;
@@ -776,6 +808,54 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
throw Exception('表达式展开过于复杂，请简化输入。');
}
// 检查是否为方程（包含等号），如果是的话，将右边的常数项移到左边
if (result.contains('=')) {
final parts = result.split('=');
if (parts.length == 2) {
final leftSide = parts[0];
final rightSide = parts[1];
// 解析左边的多项式
final leftCoeffs = _parsePolynomial(leftSide);
final rightCoeffs = _parsePolynomial(rightSide);
// 计算标准形式 ax^2 + bx + c = 0 的系数
// A = B 转换为 A - B = 0，所以右边的系数要取相反数
final a = (leftCoeffs[2] ?? 0) - (rightCoeffs[2] ?? 0);
final b = (leftCoeffs[1] ?? 0) - (rightCoeffs[1] ?? 0);
final c = (leftCoeffs[0] ?? 0) - (rightCoeffs[0] ?? 0);
// 构建标准形式的方程
String standardForm = '';
if (a != 0) {
standardForm +=
'${a == 1
? ''
: a == -1
? '-'
: a}x^2';
}
if (b != 0) {
standardForm += b > 0 ? '+${b}x' : '${b}x';
}
if (c != 0) {
standardForm += c > 0 ? '+$c' : '$c';
}
// 移除开头的加号
if (standardForm.startsWith('+')) {
standardForm = standardForm.substring(1);
}
// 如果所有系数都为0，则方程恒成立
if (standardForm.isEmpty) {
standardForm = '0';
}
result = '$standardForm=0';
}
}
return result;
}
@@ -796,13 +876,24 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
Map<int, double> _parsePolynomial(String side) {
final coeffs = <int, double>{};
// 如果输入包含括号，去掉括号
var cleanSide = side;
if (cleanSide.startsWith('(') && cleanSide.endsWith(')')) {
cleanSide = cleanSide.substring(1, cleanSide.length - 1);
}
// 扩展模式以支持 sqrt 函数
final pattern = RegExp(
r'([+-]?(?:\d*\.?\d*|sqrt\(\d+\)))x(?:\^(\d+))?|([+-]?(?:\d*\.?\d*|sqrt\(\d+\)))',
);
var s = side.startsWith('+') || side.startsWith('-') ? side : '+$side';
var s = cleanSide.startsWith('+') || cleanSide.startsWith('-')
? cleanSide
: '+$cleanSide';
for (final match in pattern.allMatches(s)) {
if (match.group(0)!.isEmpty) continue; // Skip empty matches
if (match.group(3) != null) {
// 常数项
final constStr = match.group(3)!;
@@ -893,26 +984,31 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
if (a == 0) return null;
int ac = a * c;
int absAc = ac.abs();
// Try all divisors of abs(ac) and consider both positive and negative factors
for (int d = 1; d <= sqrt(absAc).toInt(); d++) {
if (absAc % d == 0) {
int d1 = d;
int d2 = absAc ~/ d;
List<int> signs1 = ac >= 0 ? [1, -1] : [1, -1];
List<int> signs2 = ac >= 0 ? [1, -1] : [1, -1];
for (int s1 in signs1) {
for (int s2 in signs2) {
int m = s1 * d1;
int n = s2 * d2;
if (check(m, n, b)) return formatFactor(m, n, a);
m = s1 * d1;
n = s2 * (-d2);
if (check(m, n, b)) return formatFactor(m, n, a);
m = s1 * (-d1);
n = s2 * d2;
if (check(m, n, b)) return formatFactor(m, n, a);
m = s1 * (-d1);
n = s2 * (-d2);
if (check(m, n, b)) return formatFactor(m, n, a);
// Try all sign combinations for the factors
// We need m * n = ac and m + n = b
List<int> signCombinations = [1, -1];
for (int sign1 in signCombinations) {
for (int sign2 in signCombinations) {
int m = sign1 * d1;
int n = sign2 * d2;
if (m + n == b && m * n == ac) {
return formatFactor(m, n, a);
}
// Also try the swapped version
m = sign1 * d2;
n = sign2 * d1;
if (m + n == b && m * n == ac) {
return formatFactor(m, n, a);
}
}
}
}
@@ -1109,10 +1205,11 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
for (int i = 0; i < s.length; i++) {
final char = s[i];
if (char == '(')
if (char == '(') {
parenDepth++;
else if (char == ')')
} else if (char == ')') {
parenDepth--;
}
// Only split on + or - when not inside parentheses
if (parenDepth == 0 && (char == '+' || char == '-') && i > start) {