Compilare: user.cpp: In function ‘int main()’: user.cpp:5:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("camion.in","r",stdin); ^ user.cpp:6:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("camion.out","w",stdout); ^ user.cpp:7:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &k, &col); ^ user.cpp:8:73: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=k;i++) scanf("%d%d%d%d", &x1[i], &y1[i], &x2[i], &y2[i]); ^