InternBootcamp/internbootcamp/libs/bbeh_multistep_arithmetic/bbeh_arithmetic_solver.py
2025-05-23 15:27:15 +08:00

328 lines
14 KiB
Python

import math
import logging
from typing import Dict, List, Union, Optional
class BBEHArithmeticSolver:
def __init__(self):
self.operators = ['+', '-', '*', '/', '><', ';', '@', '<>', '[]', '#', '!', '~', '&', ':', '][']
self.precedence = {
'+': 1, '-': 1,
'*': 2, '/': 2,
'><': 3, ';': 3,
'@': 4, '<>': 4, '[]': 4,
'#': 5, '!': 5,
'~': 6, '&': 6,
':': 7, '][': 7
}
self.number_words = {
'one': 1, 'two': 2, 'three': 3, 'four': 4, 'five': 5,
'six': 6, 'seven': 7, 'eight': 8, 'nine': 9, 'ten': 10
}
self.logger = logging.getLogger(__name__)
self.epsilon = 1e-10
self.max_value = 1.7976931348623157e+308
self.min_value = -1.7976931348623157e+308
def solve(self, expression: str) -> float:
"""求解算术表达式"""
try:
tokens = self._tokenize(expression)
if not tokens:
return float('inf')
if not self._validate_expression_structure(tokens):
return float('inf')
return self._evaluate_expression(tokens)
except Exception as e:
self.logger.error(f"Error solving expression: {str(e)}")
return float('inf')
def _tokenize(self, expr: str) -> List[str]:
"""将表达式转换为token列表"""
try:
tokens = []
i = 0
while i < len(expr):
char = expr[i]
# 处理空格
if char.isspace():
i += 1
continue
# 处理数字单词
if char.isalpha() and (i == 0 or not expr[i - 1].isdigit()):
word = ''
while i < len(expr) and expr[i].isalpha():
word += expr[i]
i += 1
if word in self.number_words:
tokens.append(str(self.number_words[word]))
else:
raise ValueError(f"Unknown word: {word}")
continue
# 处理数字(包括科学记数法)
if char.isdigit() or (char == '-' and (not tokens or tokens[-1] in self.operators + ['('])):
num = char
i += 1
while i < len(expr) and (expr[i].isdigit() or expr[i] == '.'):
num += expr[i]
i += 1
if i < len(expr) and (expr[i] == 'e' or expr[i] == 'E'):
num += expr[i]
i += 1
if i < len(expr) and (expr[i] == '+' or expr[i] == '-'):
num += expr[i]
i += 1
while i < len(expr) and expr[i].isdigit():
num += expr[i]
i += 1
try:
float(num)
tokens.append(num)
except ValueError:
raise ValueError(f"Invalid number format: {num}")
continue
# 处理括号
if char in '()':
tokens.append(char)
i += 1
continue
# 处理运算符
if i < len(expr):
max_op_len = 3
matched = False
for length in range(max_op_len, 0, -1):
if i + length <= len(expr):
potential_op = expr[i:i + length]
if potential_op in self.operators:
tokens.append(potential_op)
i += length
matched = True
break
if not matched:
raise ValueError(f"Invalid character: {char}")
if not self._validate_expression(tokens):
raise ValueError("Invalid expression: Mismatched parentheses")
return tokens
except Exception as e:
self.logger.error(f"Error in tokenization: {str(e)}")
raise
def _validate_expression(self, tokens: List[str]) -> bool:
"""验证表达式的有效性"""
stack = []
for token in tokens:
if token == '(':
stack.append(token)
elif token == ')':
if not stack:
return False
stack.pop()
return len(stack) == 0
def _validate_expression_structure(self, tokens: List[str]) -> bool:
"""验证表达式的结构是否合法"""
stack = []
operand_count = 0
operator_count = 0
for token in tokens:
if token == '(':
stack.append(token)
elif token == ')':
if not stack:
return False
stack.pop()
elif token in self.operators:
operator_count += 1
else:
operand_count += 1
if stack:
return False
return operand_count == operator_count + 1
def _safe_float_conversion(self, value: Union[str, int, float]) -> float:
"""安全地将值转换为浮点数"""
try:
if isinstance(value, (int, float)):
if math.isinf(value) or math.isnan(value):
return float('inf') if value > 0 else float('-inf')
return float(value)
if isinstance(value, str):
try:
result = float(value)
if math.isinf(result) or math.isnan(result):
return float('inf') if result > 0 else float('-inf')
if abs(result) > self.max_value:
return float('inf') if result > 0 else float('-inf')
if abs(result) != 0 and abs(result) < self.min_value:
return 0.0
return result
except ValueError:
if value.lower() in self.number_words:
return float(self.number_words[value.lower()])
raise
raise ValueError(f"Cannot convert {type(value)} to float")
except (ValueError, TypeError) as e:
self.logger.error(f"Error in safe_float_conversion: {str(e)}")
return float('inf')
def _perform_operation(self, op: str, a: float, b: float) -> float:
"""执行具体的运算"""
try:
if math.isinf(a) or math.isinf(b):
if op in ['+', '*', '@', '<>', '[]', '#', '&']:
return float('inf') if (a > 0 or b > 0) else float('-inf')
elif op in ['-', '/', '><', ';', '!', '~', ':', '][']:
return float('inf')
if op == '/' and abs(b) < self.epsilon:
return float('inf')
def safe_operation(func):
try:
result = func()
if math.isinf(result) or math.isnan(result):
return float('inf') if result > 0 else float('-inf')
if abs(result) > self.max_value:
return float('inf') if result > 0 else float('-inf')
if abs(result) != 0 and abs(result) < self.min_value:
return 0.0
return result
except (OverflowError, ValueError, ZeroDivisionError):
return float('inf')
if op == '+':
result = safe_operation(lambda: a + b)
elif op == '-':
result = safe_operation(lambda: a - b)
elif op == '*':
result = safe_operation(lambda: a * b)
elif op == '/':
result = safe_operation(lambda: a / b if abs(b) > self.epsilon else float('inf'))
elif op == '><':
result = safe_operation(lambda: a - b if a * b > 0 else a + b)
elif op == ';':
result = safe_operation(lambda: (a - b) if a + b > 0 else a - b)
elif op == '@':
result = safe_operation(lambda: a * b if a > b else a + b)
elif op == '<>':
result = safe_operation(lambda: abs(a - b))
elif op == '[]':
result = safe_operation(lambda: max(a, b))
elif op == '#':
result = safe_operation(lambda: (a * b) if a > b else min(a, b))
elif op == '!':
result = safe_operation(lambda: (a - b) if a * b > 0 else (a + b))
elif op == '~':
result = safe_operation(lambda: (2 * b - a) if a > b else b)
elif op == '&':
result = safe_operation(lambda: (a + b) if a * b > 0 else (a - b))
elif op == ':':
result = safe_operation(lambda: (a * b) if a + b > 0 else (-a * -b))
elif op == '][':
try:
if abs(a) < 1e10 and abs(b) < 1e10:
gcd_value = self._gcd(abs(int(a)), abs(int(b)))
return safe_operation(lambda: (a - b) if gcd_value == 1 else float(gcd_value))
else:
return float('inf')
except (OverflowError, ValueError):
return float('inf')
else:
raise ValueError(f"Unknown operator: {op}")
return result
except Exception as e:
self.logger.error(f"Error in operation {op} with operands {a}, {b}: {str(e)}")
return float('inf')
def _gcd(self, a: int, b: int) -> int:
"""计算最大公约数"""
while b:
a, b = b, a % b
return a
def _evaluate_expression(self, tokens: List[str]) -> float:
"""计算表达式的值"""
try:
values = []
operators = []
for token in tokens:
try:
if token == '(':
operators.append(token)
elif token == ')':
while operators and operators[-1] != '(':
if len(values) < 2:
raise ValueError(f"Not enough operands for operator {operators[-1]}")
op = operators.pop()
b = self._safe_float_conversion(values.pop())
a = self._safe_float_conversion(values.pop())
result = self._perform_operation(op, a, b)
values.append(result)
if operators:
operators.pop()
elif token in self.operators:
while (operators and operators[-1] != '(' and
self.precedence.get(operators[-1], 0) >= self.precedence.get(token, 0)):
if len(values) < 2:
raise ValueError(f"Not enough operands for operator {operators[-1]}")
op = operators.pop()
b = self._safe_float_conversion(values.pop())
a = self._safe_float_conversion(values.pop())
result = self._perform_operation(op, a, b)
values.append(result)
operators.append(token)
else:
try:
if isinstance(token, str):
token_lower = token.lower()
if token_lower in self.number_words:
value = float(self.number_words[token_lower])
else:
value = self._safe_float_conversion(token)
values.append(value)
else:
raise ValueError(f"Invalid token type: {type(token)}")
except ValueError as ve:
self.logger.error(f"Error converting number: {token}")
raise ValueError(f"Invalid number format: {token}")
except Exception as e:
self.logger.error(f"Error processing token {token}: {str(e)}")
return float('inf')
while operators:
if len(values) < 2:
raise ValueError("Not enough operands for remaining operators")
op = operators.pop()
if op == '(':
raise ValueError("Mismatched parentheses")
b = self._safe_float_conversion(values.pop())
a = self._safe_float_conversion(values.pop())
result = self._perform_operation(op, a, b)
values.append(result)
if len(values) != 1:
raise ValueError("Invalid expression: too many values")
return values[0]
except Exception as e:
self.logger.error(f"Error evaluating expression: {str(e)}")
return float('inf')