Passing a two dimensional array, Works in C but not C++ [duplicate]

Answer 1

The array arguments you declare are variable-length arrays and those are not allowed in C++. You have to solve in in other ways, like using templates, std::vector or std::array.

Remember that C and C++ are two very different languages. C++ may have been originally developed from C, and they share syntax for many things, but they are still different languages with different rules.

Answer 2

Only C supports variable length arrays, C++ doesn't. C++ standard says that the size of the array must be a constant expression.

Use std::vector instead. Declaration should be

void mark(int n, int m, int i, int j, vector< vector<int> > &canvisit, vector< vector<int> > &a);