几个向量的笛卡尔乘积 [英] Cartesian product of several vectors

问题描述

以前曾经问过类似的问题，但我无法找到与我的问题的完全匹配。

similar questions have been asked before but I cant find an exact match to my question.

我有4个向量，每个向量包含200-500个4位整数。每个向量中元素的确切数量不同，但我可以将其修复为特定值。我需要在这4个向量中找到所有可能的元素组合。

I have 4 vectors each of which hold between 200-500 4 digit integers. The exact number of elements in each vector varies but I could fix it to a specific value. I need to find all possible combinations of the elements in these 4 vectors.

例如：

v1 [10 ，30]
v2 [11，45]
v3 [63,56]
v4 [82，98]

v1[10, 30] v2[11, 45] v3[63, 56] v4[82, 98]

得到这样的东西：

[10，11，63，82];
[30，11，63，82];
[10，45，63，82];
[10，45，56，82]等。

[10, 11, 63, 82]; [30, 11, 63, 82]; [10, 45, 63, 82]; [10, 45, 56, 82] etc..

这个算法有一个通用名称，否则任何提示在C ++实现这将是有益的。性能不是很大的问题，因为我只需要运行一次算法。

Is there a common name for this algorithm so I can find some references to it online? Otherwise any tips on implementing this in C++ would be helpful. Performance isn't much of an issue as I only need to run the algorithm once. Is there anything built into the STL?

推荐答案

没有多少算法...

for(vector<int>::const_iterator i1 = v1.begin(); i1 != v1.end(); ++i1)
    for(vector<int>::const_iterator i2 = v2.begin(); i2 != v2.end(); ++i2)
        for(vector<int>::const_iterator i3 = v3.begin(); i3 != v3.end(); ++i3)
            for(vector<int>::const_iterator i4 = v4.begin(); i4 != v4.end(); ++i4)
                cout << "[" << *i1 << "," << *i2 << "," << *i3 << "," << *i4 << "]" << endl;

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