计数整数的频率 [英] counting frequency of integers take together

问题描述

我需要在二进制文件中统计不同整数的频率，我该如何做？我不想转换为字符串，因为这将减慢我的程序下来..我想...

I need to count the frequencies of different integers together in a binary file, how can I do this? I do not wish to convert to string, because that would slow down my program down.. I think...

vector<uint32_t> buf(2);
map<uint32_t, uint32_t> mymap;

if(file.is_open())
{
    while (file.read(reinterpret_cast<char*>(&buf[0]), sizeof(uint32_t)*numcols))
    {
        for(size_t i = 0; i < numcols; ++i)
        {
            mymap[buf[i]]++; // **---> I need help here**
        }
    }
}
file.close();

如何制作地图的键，以便它总是一起计数那些整数

How can I make the key to the map so that it always counts those integers together

是的..我连续看到整数对的次数，例如多少次（1,2），（8,14）或（7,3）。

Yep.. how many times I see integer pairs consecutively, like how many times (1,2), or (8, 14), or (7,3).

1 2
1 2
7 3
8 14
8 14
8 14

1 2 --> 2 times
7 3 --> 1 time
8 14 --> 3 times

numcols == 2正确。

numcols == 2 correct.

推荐答案

一个选项可能是使用映射使用 pair< uint32_t，uint32_t> s作为键。这样，你就可以从 uint32_t 的显式映射到它们出现的频率。

One option might be to have the map use pair<uint32_t, uint32_t>s as keys. That way you're explicitly mapping from pairs of uint32_ts to the frequency with which they appear.

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