View Compilation Error

0_0_36739197_9669.cpp: In member function 'void trie::insert(ll)':
0_0_36739197_9669.cpp:23:9: error: 'exist' was not declared in this scope
         exist[p] = 1;
         ^
0_0_36739197_9669.cpp: In member function 'void trie::clear()':
0_0_36739197_9669.cpp:44:13: error: 'exist' was not declared in this scope
             exist[i]=0;
             ^