Compilare: user.cpp: In function ‘void kruskal()’: user.cpp:36:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < m && sol.size() < n-1; i++) ^ user.cpp: In function ‘void afisare()’: user.cpp:51:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) ^ user.cpp: In function ‘void citire()’: user.cpp:23:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:26:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &u[i].x, &u[i].y, &u[i].c); ^ user.cpp: In function ‘int main()’: user.cpp:57:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in", "r", stdin); ^ user.cpp:58:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out", "w", stdout); ^