Compilare: main.cpp: In function 'void prep()': main.cpp:50:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;i*=2){ ~^~~ main.cpp: In function 'int main()': main.cpp:69:23: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long long unsigned int*' [-Wformat=] fscanf(fin,"%d",&n); ^ main.cpp:71:31: warning: format '%d' expects argument of type 'int', but argument 3 has type 'long long unsigned int' [-Wformat=] fprintf(fout,"%d", b[0][1]); ^ main.cpp:69:24: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^