View Compilation Error

0_0_32536506_10940.cpp: In member function 'void<anonymous struct>::build()':
0_0_32536506_10940.cpp:41:29: error: 'cnt' was not declared in this scope
         for(int i = 1; i <= cnt; i++) update(root[i],root[i-1],1,n+1,a[i]);
                             ^