·If you want to use the memset function to assign an array for the first time, then there can be unknowns in the brackets in the array you previously defined, such as int hash[numssize];
·If you don’t want to use the memset function to assign values to the array for the first time, but directly use the method such as int hash[100]={0}, then there can be no unknowns in the brackets in the array you defined earlier, that is, int hash[ numssize]={0} is not possible, and the disadvantage of this assignment method is that it can only assign all the arrays to 0.
·The *returnsize in Leikou means to let you write out the size of the array you want to return, so you can define a very large array to prevent it from crossing the boundary, and it must not be used up, so when we return Use this to write the returned size directly, so that the system only reads a part of this large array.