《Cracking the Coding Interview》——第11章：排序和搜索——题目4

2014-03-21 21:28

题目：给定一个20GB大小的文本文件，每一行都是一个字符串。请设计方法将这个文件里的字符串排序。

解法：请看下面的注释。

代码：

// 11.4 Given a file of 20GB containing strings, one word each line. How would you sort them all?
// Answer:
//    1. Split them into 200M pieces.
//    2. For each pieces, use comparison sort or hashing to sort it in memory.
//    3. After sorting each pieces, output it back to a file.
//    4. Merge the 100 pieces with multiprocess, speed up the merging with a heap or something.
//    5. You can't load all full pieces into memory, load one small piece of a piece at a time.
//    6. When this small piece is merged into final result, load the next small piece.
//    7. I suppose it's completely acceptable for a relatively good PC to afford such IO and computation.
int main()
{
    return 0;
}