View Compilation Error

0_0_18096639_4345.cpp: In function 'int find_trie(char*)':
0_0_18096639_4345.cpp:54:12: error: no match for 'operator=' (operand types are 'trie' and 'int')
         id = str[i] - 'a';
            ^
0_0_18096639_4345.cpp:54:12: note: candidates are:
0_0_18096639_4345.cpp:20:16: note: trie& trie::operator=(const trie&)
 typedef struct trie
                ^
0_0_18096639_4345.cpp:20:16: note:   no known conversion for argument 1 from 'int' to 'const trie&'
0_0_18096639_4345.cpp:20:16: note: trie& trie::operator=(trie&&)
0_0_18096639_4345.cpp:20:16: note:   no known conversion for argument 1 from 'int' to 'trie&&'
0_0_18096639_4345.cpp:55:19: error: no match for 'operator[]' (operand types are 'trie* [26]' and 'trie')
         if(p->next[id]==NULL)
                   ^
0_0_18096639_4345.cpp:57:20: error: no match for 'operator[]' (operand types are 'trie* [26]' and 'trie')
         p = p->next[id];
                    ^