Compilare: user.cpp: In function ‘unsigned int __find(int)’: user.cpp:18:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( father[root] != root ) ^ user.cpp: In function ‘int main()’: user.cpp:50:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bile.in" , "r" , stdin); ^ user.cpp:51:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bile.out" , "w" , stdout); ^ user.cpp:53:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:59:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &mem[i][0] , &mem[i][1] ); ^