Compilare: user.cpp: In function ‘int couple(int, int)’: user.cpp:48:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘void kruskal()’: user.cpp:79:13: warning: variable ‘c’ set but not used [-Wunused-but-set-variable] int a,b,c; ^ user.cpp: In function ‘void read()’: user.cpp:59:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&Q); ^ user.cpp:62:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m[i][j]); ^ user.cpp: In function ‘void solve()’: user.cpp:186:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x1,&y1,&x2,&y2); ^ user.cpp: In function ‘int main()’: user.cpp:210:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("matrice2.in","r",stdin); ^ user.cpp:211:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("matrice2.out","w",stdout); ^