Compilare: user.cpp: In function ‘int main()’: user.cpp:133:14: warning: unused variable ‘sol’ [-Wunused-variable] int cont,sol = 0; ^ user.cpp:39:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.in","r",stdin); ^ user.cpp:40:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.out","w",stdout); ^ user.cpp:44:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%d %d",&n,&N,&M); ^ user.cpp:50:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&d[i].i1,&d[i].j1,&d[i].i2,&d[i].j2); ^