Compilare: main.cpp: In function 'int main()': main.cpp:53:30: warning: suggest parentheses around '-' inside '<<' [-Wparentheses] val = 1<<(nrfact[i]) - 1; ~~~~~~~~~~~~^~~ main.cpp:26:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ main.cpp:29:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &x); ^