Eroare de compilare: user.cpp:1:85: 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:1:121: error: ‘fopen’ was not declared in this scope 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:1:135: error: ‘fscanf’ was not declared in this scope 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:1:185: error: ‘fprintf’ was not declared in this scope 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));} ^