View Compilation Error

0_0_17415774_28304.cpp: In function 'void run()':
0_0_17415774_28304.cpp:13:2: error: expected unqualified-id before 'int'
  int u=2;
  ^
0_0_17415774_28304.cpp:54:8: error: 'u' was not declared in this scope
    ans[u++]=num[(i+1)/2];
        ^
0_0_17415774_28304.cpp:57:12: error: 'u' was not declared in this scope
  for(i=1;i<u;i++)
            ^