View Compilation Error

0_0_36784110_10742.cpp: In function 'void init()':
0_0_36784110_10742.cpp:13:32: error: 'k' was not declared in this scope
     for(int i=0;i<=tot;i++) tr[k].lc=tr[k].rc=tr[k].v=tr[k].lz=0;
                                ^