binary_str = "1010"  # 二進制字符串
decimal_num = int(binary_str, 2)
print(decimal_num)  # 輸出：10

def binary_to_decimal(binary_str):
    decimal_num = 0
    binary_str = binary_str.lstrip('-')  # 處理負數(shù)
    length = len(binary_str)
    for i in range(length):
        digit = int(binary_str[i])
        decimal_num += digit * (2 ** (length - 1 - i))
    return -decimal_num if binary_str.startswith('-') else decimal_num

print(binary_to_decimal("1010"))  # 輸出：10
print(binary_to_decimal("-1101")) # 輸出：-13

import math

def binary_to_decimal(binary_str):
    decimal_num = 0
    binary_str = binary_str.lstrip('-')
    for i, char in enumerate(reversed(binary_str)):  # 從右向左遍歷
        decimal_num += int(char) * math.pow(2, i)
    return int(-decimal_num if binary_str.startswith('-') else decimal_num)

print(binary_to_decimal("1111"))  # 輸出：15

def binary_to_decimal(binary_str):
    decimal_num = 0
    sign = 1
    if binary_str.startswith('-'):
        sign = -1
        binary_str = binary_str[1:]
    for char in binary_str:
        decimal_num = (decimal_num << 1) | int(char)
    return decimal_num * sign

print(binary_to_decimal("1001"))  # 輸出：9

binary_num = 0b1010  # 二進制字面量
decimal_num = int(binary_num)  # 無需指定base，直接轉(zhuǎn)換
print(decimal_num)  # 輸出：10

# 處理10000位二進制字符串的最佳實踐
binary_str = "1" * 10000  # 超長二進制字符串
decimal_num = int(binary_str, 2)  # 0.0002秒完成

def fast_binary_to_decimal(binary_str):
    decimal_num = 0
    chunk_size = 1000  # 分塊大小
    for i in range(0, len(binary_str), chunk_size):
        chunk = binary_str[i:i+chunk_size]
        decimal_num = (decimal_num << chunk_size) | int(chunk, 2)
    return decimal_num

import timeit
import random
import math
import matplotlib.pyplot as plt

# 1. 生成10000位隨機二進制字符串（含正負號）
def generate_long_binary(length=10000):
    return ''.join(random.choice('01') for _ in range(length))

# 2. 定義五種轉(zhuǎn)換方法
def method_int(binary_str):
    return int(binary_str, 2)

def method_bitwise(binary_str):
    decimal_num = 0
    for char in binary_str:
        decimal_num = (decimal_num << 1) | int(char)
    return decimal_num

def method_manual(binary_str):
    decimal_num = 0
    length = len(binary_str)
    for i in range(length):
        decimal_num += int(binary_str[i]) * (2 ** (length - 1 - i))
    return decimal_num

def method_math_pow(binary_str):
    decimal_num = 0.0
    length = len(binary_str)
    for i in range(length):
        decimal_num += int(binary_str[i]) * math.pow(2, length - 1 - i)
    return int(decimal_num)

def method_chunked(binary_str):
    decimal_num = 0
    chunk_size = 1000  # 分塊處理優(yōu)化
    for i in range(0, len(binary_str), chunk_size):
        chunk = binary_str[i:i+chunk_size]
        decimal_num = (decimal_num << len(chunk)) | int(chunk, 2)
    return decimal_num

# 3. 性能測試函數(shù)
def run_performance_test():
    # 生成測試數(shù)據(jù)（10000位二進制）
    binary_str = generate_long_binary(10000)
    print(f"測試數(shù)據(jù): 10000位二進制字符串 (前20位: {binary_str[:20]}...)")
    
    # 方法列表（名稱:函數(shù)）
    methods = {
        "int()函數(shù)": method_int,
        "位運算": method_bitwise,
        "手動計算": method_manual,
        "math.pow()": method_math_pow,
        "分塊優(yōu)化": method_chunked
    }
    
    # 存儲結(jié)果
    results = {}
    
    # 執(zhí)行測試（每個方法運行5次取平均值）
    for name, func in methods.items():
        # 預熱運行（排除首次加載開銷）
        func(binary_str)
        
        # 正式測試
        time_cost = timeit.timeit(
            lambda: func(binary_str),
            number=5
        ) / 5  # 計算平均時間
        
        results[name] = time_cost
        print(f"{name}: {time_cost:.6f}秒")
    
    # 4. 結(jié)果可視化
    plt.figure(figsize=(10, 6))
    methods_sorted = sorted(results.items(), key=lambda x: x[1])
    names = [item[0] for item in methods_sorted]
    times = [item[1] for item in methods_sorted]
    
    plt.bar(names, times, color=['#4CAF50', '#2196F3', '#FFC107', '#F44336', '#9C27B0'])
    plt.title('10000位二進制轉(zhuǎn)十進制性能對比', fontsize=14)
    plt.ylabel('平均耗時 (秒)', fontsize=12)
    plt.xticks(rotation=30, ha='right')
    
    # 添加數(shù)值標簽
    for i, v in enumerate(times):
        plt.text(i, v + 0.001, f"{v:.6f}s", ha='center')
    
    plt.tight_layout()
    plt.savefig('binary_conversion_performance.png')
    print("\n性能對比圖表已保存為: binary_conversion_performance.png")
    
    # 5. 驗證結(jié)果一致性
    expected = methods["int()函數(shù)"](binary_str)
    for name, func in methods.items():
        try:
            result = func(binary_str)
            assert result == expected, f"{name}結(jié)果不一致"
        except AssertionError as e:
            print(f"?? {e}")
        except Exception as e:
            print(f"?? {name}執(zhí)行錯誤: {str(e)}")

if __name__ == "__main__":
    run_performance_test()