View Compilation Error

0_0_22932784_7401.cpp: In function 'int main()':
0_0_22932784_7401.cpp:41:14: error: 'j' was not declared in this scope
   while(a[n][j]==0)
              ^
0_0_22932784_7401.cpp:45:20: error: 'j' was not declared in this scope
   printf("%d",a[n][j++]);
                    ^