View Compilation Error

0_0_17753886_3075.cpp: In function 'void init()':
0_0_17753886_3075.cpp:9:12: error: 'mat' was not declared in this scope
     memset(mat,0,sizeof(mat));
            ^
0_0_17753886_3075.cpp: In function 'void work()':
0_0_17753886_3075.cpp:15:5: error: 'LL' was not declared in this scope
     LL ans=0,sum=0;
     ^
0_0_17753886_3075.cpp:19:14: error: 'sum' was not declared in this scope
         a=(a+sum)%n;b=(b+sum)%n;sum=0;
              ^
0_0_17753886_3075.cpp:23:9: error: 'ans' was not declared in this scope
         ans+=sum;
         ^
0_0_17753886_3075.cpp:25:22: error: 'ans' was not declared in this scope
     printf("%I64d\n",ans);
                      ^