Compilare: user.cpp: In function ‘int main()’: user.cpp:86:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm2.in","r",stdin);freopen("apm2.out","w",stdout); ^ user.cpp:86:64: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm2.in","r",stdin);freopen("apm2.out","w",stdout); ^ user.cpp:88:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&M,&Q); ^ user.cpp:91:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&v[i].x,&v[i].y,&v[i].cost); ^ user.cpp:97:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^