Compilare: user.cpp:2:85: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] long long c(int n){long long i,s=1;for(i=1;i*i<=n;i++)s+=2*(n/i-i)+1;return s;}main(){int a,b;fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);fprintf(fopen("ndiv.out","w"),"%lld",c(b)-c(a-1));} ^ user.cpp: In function ‘int main()’: user.cpp:2:136: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] long long c(int n){long long i,s=1;for(i=1;i*i<=n;i++)s+=2*(n/i-i)+1;return s;}main(){int a,b;fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);fprintf(fopen("ndiv.out","w"),"%lld",c(b)-c(a-1));} ^