import numpy as np

print("=" * 50)
print("BoW忽略词序的演示")
print("=" * 50)

def simple_bow(docs):
    vocab_set = set()
    for doc in docs:
        vocab_set.update(doc)
    vocab = sorted(list(vocab_set))
    bow_matrix = []
    for doc in docs:
        vec = [0] * len(vocab)
        for word in doc:
            if word in vocab:
                vec[vocab.index(word)] += 1
        bow_matrix.append(vec)
    return vocab, bow_matrix

docs = [
    ["我", "爱", "你"],      
    ["你", "爱", "我"],      
    ["爱你我"],             
]

vocab, bow_matrix = simple_bow(docs)

print("文档：")
for i, doc in enumerate(docs):
    print(f"  Doc{i+1}: {''.join(doc)}")
print()

print("BoW矩阵：")
for i, vec in enumerate(bow_matrix):
    print(f"  Doc{i+1}: {vec}")
print()

print(f"词表: {vocab}")
print()

print("问题：这三个完全不同的句子，BoW向量完全相同！")
print("Doc1: 我爱你（表达爱意）")
print("Doc2: 你爱我（对方爱我）")
print("Doc3: 爱你我（意义不明）")
print()
print("结论：BoW模型丢失了词序信息！")