犯罪率因素分析（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/crime1.csv'
    df = pd.read_csv(url)
    
    fig, axes = plt.subplots(2, 2, figsize=(14, 10))
    if 'narr86' in df.columns:
        axes[0,0].hist(df['narr86'], bins=15, color='red', edgecolor='black', alpha=0.7)
        axes[0,0].set_title('犯罪记录分布')
    axes[0,1].scatter(df['pcnv'] if 'pcnv' in df.columns else df.iloc[:,0], df['narr86'] if 'narr86' in df.columns else df.iloc[:,1], alpha=0.3, color='blue')
    axes[0,1].set_title('定罪率 vs 犯罪')
    if 'avgsen' in df.columns:
        axes[1,0].boxplot([df['avgsen']], labels=['刑期'])
        axes[1,0].set_title('刑期分布')
    if 'qemp86' in df.columns:
        axes[1,1].hist(df['qemp86'], bins=15, color='teal', edgecolor='black', alpha=0.7)
        axes[1,1].set_title('就业季度分布')
    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"