View Compilation Error

0_0_25442140_16793.cpp: In function 'int main()':
0_0_25442140_16793.cpp:42:9: error: 'flag' was not declared in this scope
         flag = 0;
         ^
0_0_25442140_16793.cpp:48:16: error: 'pd' was not declared in this scope
             if(pd == 0)
                ^
0_0_25442140_16793.cpp:50:13: error: 'pd' was not declared in this scope
             pd= trie_insert(l);
             ^
0_0_25442140_16793.cpp:53:12: error: 'pd' was not declared in this scope
         if(pd == 0) printf("NO\n");
            ^