Compilare: user.cpp: In function ‘void solve()’: user.cpp:21:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘void read()’: user.cpp:10:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("progresii.in", "r", stdin); ^ user.cpp:11:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lld %lld", &n, &m, &k, &l); ^ user.cpp:15:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &p[i]); ^ user.cpp: In function ‘void write()’: user.cpp:32:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("progresii.out", "w", stdout); ^