Compilare: user.cpp: In function ‘int main()’: user.cpp:53:18: warning: unused variable ‘length’ [-Wunused-variable] int i, j, k, length, nrc, pos, pluton = 0, NR = 0, NR_max = 0, c, nrcif; ^ user.cpp:50:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.in", "r", stdin); ^ user.cpp:51:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.out", "w", stdout); ^ user.cpp: In function ‘void get_number(long long int&)’: user.cpp:31:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dmax, stdin); ^ user.cpp:42:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dmax, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:53:31: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i, j, k, length, nrc, pos, pluton = 0, NR = 0, NR_max = 0, c, nrcif; ^