Eroare de compilare: user.cpp:102:23: error: expected unqualified-id before ‘union’ void DisjointDataSet::union(int x, int y) ^ user.cpp: In function ‘int main(int, char**)’: user.cpp:130:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (operation == 2) ^ user.cpp:118:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &n, &m); ^ user.cpp:125:45: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d %d", &operation, &x, &y); ^