Compilare: user.cpp: In function ‘int main()’: user.cpp:155:9: warning: unused variable ‘j’ [-Wunused-variable] int j; ^ user.cpp:132:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("calcul.in", "r", stdin); ^ user.cpp:135:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(nr, N, stdin); ^ user.cpp:140:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(nr, N, stdin); ^ user.cpp:150:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &c); ^