Compilare: main.cpp: In function 'int main()': main.cpp:106:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<prime.size() && 1LL*prime[i]*prime[i] <= x;i++) ~^~~~~~~~~~~~~ main.cpp:93:13: warning: unused variable 'j' [-Wunused-variable] int t,i,j; ^ main.cpp: In member function 'char Parser::getChar()': main.cpp:16:48: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(str, sizeof(char), SIZE, fin); ^