Compilare: user.cpp: In function ‘void get_cost()’: user.cpp:56:31: warning: unused variable ‘c’ [-Wunused-variable] int i, k = 0, c; ^ user.cpp: In function ‘void read()’: user.cpp:28:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adn.in", "r", stdin); ^ user.cpp:29:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:32:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s[i] + 1); ^ user.cpp: In function ‘void write()’: user.cpp:119:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adn.out", "w", stdout); ^