CEO薪资分析面板（多子图）

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    import numpy as np
    
    url = 'https://liangdaima.com/static/data/wooldridge/ceosal1.csv'
    df = pd.read_csv(url)
    
    fig, axes = plt.subplots(2, 2, figsize=(14, 10))
    axes[0,0].hist(df['salary'], bins=20, color='navy', edgecolor='black', alpha=0.7)
    axes[0,0].set_title('薪资分布')
    axes[0,1].scatter(np.log10(df['sales']), np.log10(df['salary']), alpha=0.5, color='purple')
    axes[0,1].set_title('销售额 vs 薪资（对数）')
    axes[1,0].scatter(df['roe'], df['salary'], alpha=0.5, color='teal')
    axes[1,0].set_title('ROE vs 薪资')
    axes[1,1].boxplot([df['salary']], labels=['薪资'])
    axes[1,1].set_title('薪资箱线图')
    for ax in axes.flat:
        ax.grid(alpha=0.3)
    plt.tight_layout()
    plt.show()
    return "可视化代码执行完成"