خطاهای این برنامه ماتریس کجاست

[kanani]

#include<iostream.h>
#include<conio.h>
int menu();
int multi();
void add();
void sub();
class mat{
int mat1[2][3],mat2[3][4],mat3[2][4]={0};
int i,j,k;
public:
for(i=0;i<2;i++)
for(j=0;j<3;j++){
cout<<"enter mat1["<<i<<"]["<<j<<"]:";
cin>>mat1[i][j];
}
for(i=0;i<3;i++)
for(j=0;j<4;j++)
cout<<"enter mat2["<<i<<"]["<<j<<"]:";
cin>>mat2[i][j];
}
}
void print(){
for(i=0;i<2;i++)
for(j=0;j<4;j++)
cout<<mat3[i][j]<<" ";
cout<<endl;
};
}
int main(){
int i,c;
for(;;){
clrscr();
c=menu();
switch(c){
case1:
if(i==-1)
cout<<"\n list is full ....";
getch();
}
case2:
multi();
breake;
case3:
add();
breake;
case4:
sub();
breake;
case5:
exit(0);
}
}
}
int menu(){
int c;
cout<<"1)perform multi.";
cout<<"2)perform add.";
cout<<"3)perform sub.";
cin>>c;
return c;
}
int multi(){
for(i=0;i<2;i++)
for(j=0;j<4;j++)
mat3[i][j]=0;
for(k=0;k<3;k++)
mat3[i][j]=mat3[i][j]+mat1[i][k]*mat2[k][j];
return -1;
}
void add(){
for(i=0;i<2;i++)
for(j=0;j<4;j++)
mat3[i][j]=0;
mat3[i][j]=mat1[i][j]+mat2[i][j];
}
void sub(){
for(i=0;i<2;i++)
for(j=0;j<4;j++)
mat3[i][j]=0;
mat3[i][j]=mat1[i][j]-mat2[i][j];
}