I. Details of the error
array type has an incomplete element type
Second, error analysis
·1) Error code:

int readInfo(int B[][],int n);
int findMax(int B[][],int n,int m);

2) Error reasons:

Void Func(int array[3][10])
void Func(int array[][10])
)
; void Func(int array[][10])
)
void Func(int array[][10])
3) Correction code:

int readInfo(int B[2][40],int n);
int findMax(int B[2][40],int n,int m);