Compilare: user.cpp: In function ‘int main()’: user.cpp:21:28: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] for (j=1;j*j<=i;j++) if (i%j==0) if (j*j!=i) S+=j+i/j; ^ user.cpp:9:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv2.in","r",stdin); ^ user.cpp:10:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv2.out","w",stdout); ^ user.cpp:11:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:14:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&st[i],&dr[i]); ^