Compilare: user.c: In function ‘Initialize’: user.c:11:20: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] head = (struct node*)malloc(sizeof(struct node)); ^ user.c:11:26: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] head = (struct node*)malloc(sizeof(struct node)); ^ user.c: In function ‘Insert’: user.c:20:5: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration] char i, j, len = strlen(word), index; ^ user.c:20:22: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] char i, j, len = strlen(word), index; ^ user.c:22:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i=0; i<len; i++, ptr = ptr -> next[index]){ ^ user.c:23:9: warning: implicit declaration of function ‘tolower’ [-Wimplicit-function-declaration] index = tolower(word[i]) - 'a'; ^ user.c:23:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] user.c:25:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(ptr -> next[index] == NULL){ ^ user.c:26:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] ptr -> next[index] = (struct node*)malloc(sizeof(struct node)); ^ user.c:26:48: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] ptr -> next[index] = (struct node*)malloc(sizeof(struct node)); ^ user.c:27:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] (ptr -> next[index]) -> occurences = 0; ^ user.c:30:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] (ptr -> next[index]) -> next[j] = NULL; ^ user.c:30:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] user.c: In function ‘Search’: user.c:37:19: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] char i, len = strlen(word), index; ^ user.c:39:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i=0; i<len; i++, ptr = ptr -> next[index]){ ^ user.c:40:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] index = tolower(word[i]) - 'a'; ^ user.c:41:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(ptr -> next[index] == NULL) return 0; ^