Compilare: user.cpp: In function ‘int main()’: user.cpp:44:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(c)){ ^ user.cpp:38:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compresie.in","r",stdin); ^ user.cpp:39:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compresie.out","w",stdout); ^ user.cpp:42:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(c,1000001,stdin); ^