Compilare: user.cpp: In function ‘int main()’: user.cpp:13:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(n);i++){ ^ user.cpp:8:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text.in","r",stdin); ^ user.cpp:9:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text.out","w",stdout); ^ user.cpp:11:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(n,1000000,stdin); ^