have some problem in C++ matrix

i would like to make a code for matrix. the value of both matrix is random and the addition, subtraction,multiply and transpose function. i have some problem in the multiply fucntion, can someone help ?? thank! :p

Code:

#include <iostream>
#include <ctime>

using namespace std;

typedef struct{
	int x[3][3];
	
}Matrix3X3;

[COLOR=Green]//prototype[/COLOR]
bool isEqual (Matrix3X3 A, Matrix3X3 B);
bool isSameDimension (Matrix3X3 A, Matrix3X3 B);
bool isDefined (Matrix3X3 A, Matrix3X3 B);
Matrix3X3 addMatrices (Matrix3X3 A, Matrix3X3 B);
Matrix3X3 subtractMatrices (Matrix3X3 A, Matrix3X3 B);
Matrix3X3 multiplyMatrices (Matrix3X3 A, Matrix3X3 B);
Matrix3X3 transposeMatrix (Matrix3X3 A);

	void main(){
		Matrix3X3 A;
		Matrix3X3 B;

		[COLOR=Green]// initialise the matrix[/COLOR]
		for (int i=0;i<3;i++){
			for (int j=0;j<3;j++){
				A.x[i][j] = (rand()*time(0))% 100;
		        B.x[i][j] = (rand()*time(0))% 100;
			}
		}

     [COLOR=Green]   // print out the matrix A[/COLOR]
		cout<<"Matrix A"<<endl;
		for (int i=0;i<3;i++){
			for (int j=0;j<3;j++){
				cout<<A.x[i][j]<< " ";
	}
	cout<<endl;
	}
        [COLOR=Green] // print out the matrix B  [/COLOR] 
		cout<<"\nMatrix B"<<endl;
		for (int i=0;i<3;i++){
			for (int j=0;j<3;j++){
				cout<<B.x[i][j]<< " ";
	}
	cout<<endl;
	}
addMatrices (A,B);
subtractMatrices (A,B);
[COLOR=Green]//multiplyMatrices (A,B);[/COLOR]
transposeMatrix (A);

	cin.get();
	}
	Matrix3X3 transposeMatrix (Matrix3X3 A){
		Matrix3X3 answer;
		[COLOR=Green]//transpose the matrix[/COLOR]
		for(int i = 0;i<3;i++) { 
          for(int j=0;j<3;j++) { 
              answer.x[i][j] = A.x[j][i]; 
           }
       }
		cout<<"\nThe Transpose Results:"<<endl;
	      for(int i = 0;i<3;i++){
		  for(int j=0;j<3;j++){
			cout <<answer.x[i][j] << "\t" ;
			} cout <<endl;
		  }
		return answer;
	}
	Matrix3X3 multiplyMatrices (Matrix3X3 A, Matrix3X3 B){
		Matrix3X3 answer;
[COLOR=Green]		//before multipllication process, try to check against the 2 matrices are defined
		//or not (use isDefined method        
	
	[/COLOR]
	return answer;
	}
	
	Matrix3X3 subtractMatrices (Matrix3X3 A, Matrix3X3 B){
		Matrix3X3 answer;
      [COLOR=Green]  //before subtraction process, try to check against the dimension[/COLOR]
		
		   for(int i = 0;i<3;i++){
         for(int j=0;j<3;j++){ 
            answer.x[i][j] = (A.x[i][j] - B.x[i][j]);
			}
		   }
		   cout<<"\nThe Subtraction Results:"<<endl;
	      for(int i = 0;i<3;i++){
		  for(int j=0;j<3;j++){
			cout <<answer.x[i][j] << "\t" ;
			} cout <<endl;
		  } return answer;
		}		
	
	Matrix3X3 addMatrices (Matrix3X3 A, Matrix3X3 B){
		Matrix3X3 answer;
      
      for(int i = 0;i<3;i++){
         for(int j=0;j<3;j++){ 
            answer.x[i][j] = (A.x[i][j] + B.x[i][j]);
			}
		
	  }
     
	  cout<<"\nThe Addition Results:"<<endl;
	      for(int i = 0;i<3;i++){
		  for(int j=0;j<3;j++){
			cout <<answer.x[i][j] << "\t" ;
			} cout <<endl;
		  } return answer;
		}		
	
	
bool isDefined (Matrix3X3 A, Matrix3X3 B){
		
[COLOR=Green]		//make sure the first matrix row is column to seceond matrix row, then 2 matrices only
        // considered multipilicable[/COLOR]
return true;
}
bool isSameDimension (Matrix3X3 A, Matrix3X3 B)
{
	    
[COLOR=Green]    //first check the dimension
	//if deimension is not equal then return false else proceed[/COLOR]
return true;
	} 
	[COLOR=Green]//function body[/COLOR]
bool isEqual (Matrix3X3 A, Matrix3X3 B){
		if (isSameDimension(A,B)){
[COLOR=Green]	
	//loop thru 2 matrices and check each coontent
    //if one of the entry is not equal then return false
	//if finish loop then return true.[/COLOR]
		}
		else{
			cout<<"The matrix dimension is not equal"<<endl;
			return false;
		}
		return true;
	}

 

Multiplication function could be.....

Matrix3X3 multiplyMatrices (Matrix3X3 A, Matrix3X3 B){
Matrix3X3 answer;

Code:

for(int i = 0;i<3;i++){
for(int j=0;j<3;j++){ 
answer.x[i][j] = 0;
for (int k = 0; k<3; k++){
answer.x[i][j] += (A.x[i][k] * B.x[k][j]);
}
}
}

cout<<"\nThe Multiplication Results:"<<endl;
for(int i = 0;i<3;i++){
for(int j=0;j<3;j++){
cout <<answer.x[i][j] << "\t" ;
} cout <<endl;
} return answer;
} 

 

Yeah...i know it. my problem is at below tat boolean function, it make my multiply function cant work.... i need some help at there. thx

 

Ok. Before multiplying matrices A and B, you want to check whether columns in matrix A matches with rows in matrix B in IsDefined function. But I think this is not required in your case because matrix size is hard-coded to [3][3] in which rows and colums are equal to 3.

 

Ya....my matrix size is setted [3][3] but i still need to write it out. i not so good in boolean and i am so confuse in those 3 boolean function..can you give me an example or tips? thx!