Compilare: user.c:1:17: warning: return type defaults to ‘int’ [-Wimplicit-int] long long i=1,s;main(a,b){fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);for(;i*i<=b;i++)s+=2*(b/i-i)+1;for(i=1;i*i<a;i++)s-=2*((a-1)/i-i)+1;fprintf(fopen("ndiv.out","w"),"%lld",s);} ^ user.c: In function ‘main’: user.c:1:17: warning: type of ‘a’ defaults to ‘int’ [-Wimplicit-int] user.c:1:17: warning: type of ‘b’ defaults to ‘int’ [-Wimplicit-int] user.c:1:27: warning: implicit declaration of function ‘fscanf’ [-Wimplicit-function-declaration] long long i=1,s;main(a,b){fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);for(;i*i<=b;i++)s+=2*(b/i-i)+1;for(i=1;i*i<a;i++)s-=2*((a-1)/i-i)+1;fprintf(fopen("ndiv.out","w"),"%lld",s);} ^ user.c:1:27: warning: incompatible implicit declaration of built-in function ‘fscanf’ user.c:1:27: note: include ‘<stdio.h>’ or provide a declaration of ‘fscanf’ user.c:1:34: warning: implicit declaration of function ‘fopen’ [-Wimplicit-function-declaration] long long i=1,s;main(a,b){fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);for(;i*i<=b;i++)s+=2*(b/i-i)+1;for(i=1;i*i<a;i++)s-=2*((a-1)/i-i)+1;fprintf(fopen("ndiv.out","w"),"%lld",s);} ^ user.c:1:34: warning: passing argument 1 of ‘fscanf’ makes pointer from integer without a cast [-Wint-conversion] user.c:1:34: note: expected ‘void *’ but argument is of type ‘int’ user.c:1:137: warning: implicit declaration of function ‘fprintf’ [-Wimplicit-function-declaration] long long i=1,s;main(a,b){fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);for(;i*i<=b;i++)s+=2*(b/i-i)+1;for(i=1;i*i<a;i++)s-=2*((a-1)/i-i)+1;fprintf(fopen("ndiv.out","w"),"%lld",s);} ^ user.c:1:137: warning: incompatible implicit declaration of built-in function ‘fprintf’ user.c:1:137: note: include ‘<stdio.h>’ or provide a declaration of ‘fprintf’ user.c:1:145: warning: passing argument 1 of ‘fprintf’ makes pointer from integer without a cast [-Wint-conversion] long long i=1,s;main(a,b){fscanf(fopen("ndiv.in","r"),"%d%d",&a,&b);for(;i*i<=b;i++)s+=2*(b/i-i)+1;for(i=1;i*i<a;i++)s-=2*((a-1)/i-i)+1;fprintf(fopen("ndiv.out","w"),"%lld",s);} ^ user.c:1:145: note: expected ‘void *’ but argument is of type ‘int’