How to use a class as a key of a map when the class contains a 2d array?

Question

I have a class which looks like the following:

class A{
   private:
   int *a[10];
};

Now I want to have a map which will have the mentioned class as it's key.

map<A,int> visited;

How can I overload the less operator/write a compare function here so that the map can identify duplicate 2D arrays? I have written a overloader inside the class. But, it's treating objects containing duplicate arrays as different objects. This is the function I have written:

bool operator<(const A& other) const{
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(a[i][j]!=other.a[i][j])return true;
        }
    }
    return false;
 }

I can't find the problem in the code. Can somebody please help?

Answer 1

bool operator<(const A& other) const{
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(a[i][j]==other.a[i][j]) continue;
            return a[i][j]<other.a[i][j];
        }
    }
    return false;
}

这应该适用于地图。但如果阵列很大，它可能会很慢。考虑编写一个哈希函数并使用unordered_map。