Compilare: user.cpp: In function ‘int main()’: user.cpp:15:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=2;i<strlen(s);i++) ^ user.cpp:26:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<strlen(s);i++) ^ user.cpp:33:17: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[i]=NULL; ^ user.cpp:11:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%c",&h,&c); ^ user.cpp:12:22: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,100001,f); ^