有关 CS144 Lab1 的一个疑问 about skr_learning HOT 5 CLOSED

// 获取当前子串的新起始位置
size_t new_idx = -1;
// 如果前面确实有子串
if (pos_iter != _unassemble_strs.end() && pos_iter->first <= index) {
    const size_t up_idx = pos_iter->first;

    // 如果当前子串前面出现了重叠
    if (index < up_idx + pos_iter->second.size())
        new_idx = up_idx + pos_iter->second.size();
}
// 如果前面没有子串，则和当前读取到的pos进行比较
else if (index < _next_assembled_idx)
    new_idx = _next_assembled_idx;
else
    new_idx = index;

// 获取当前子串的新起始位置
size_t new_idx = -1;
// 如果前面确实有子串
if (pos_iter != _unassemble_strs.end() && pos_iter->first <= index) {
    const size_t up_idx = pos_iter->first;

    // 如果当前子串前面出现了重叠
    if (index < up_idx + pos_iter->second.size())
        new_idx = up_idx + pos_iter->second.size();
    /* -------------------------------------------------------------------------------- */
    else {
        /* NOP, 这里的 new_idx 应该为 index，但是因为没有赋值结果却为 -1 */
    }
    /* -------------------------------------------------------------------------------- */
}
// 如果前面没有子串，则和当前读取到的pos进行比较
else if (index < _next_assembled_idx)
    new_idx = _next_assembled_idx;
else
    new_idx = index;