Compilare: user.cpp: In function ‘int main()’: user.cpp:18:15: warning: unused variable ‘j’ [-Wunused-variable] int m, i, j, x, y, c, k; ^ user.cpp:18:27: warning: unused variable ‘k’ [-Wunused-variable] int m, i, j, x, y, c, k; ^ user.cpp:15:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.in","r",stdin); ^ user.cpp:16:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("disjoint.out","w",stdout); ^ user.cpp:20:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:23:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&c,&x,&y); ^