中缀表达式转换成后缀

以下是中缀表达式转换成后缀的过程：

def infix_to_postfix(infix):
    precedence = {'+': 1, '-': 1, '*': 2, '/': 2, '^': 3}
    stack = []
    postfix = ''
    for char in infix:
        if char.isalnum():
            postfix += char
        elif char == '(':
            stack.append(char)
        elif char == ')':
            while stack and stack[-1] != '(':
                postfix += stack.pop()
            stack.pop()
        else:
            while stack and stack[-1] != '(' and precedence[stack[-1]] >= precedence[char]:
                postfix += stack.pop()
            stack.append(char)
    while stack:
        postfix += stack.pop()
    return postfix

infix_expression = "1+((2+3)*4)-5"
print("Infix Expression:", infix_expression)
print("Postfix Expression:", infix_to_postfix(infix_expression)) # 输出：123+4*+5-