src.cpp:3:30: error: size of array 'a' is too large
long long int v,i,a[999999999];
^
src.cpp: In function 'int main()':
src.cpp:8:10: error: 'a' was not declared in this scope
cin>>a[i];
^
src.cpp:9:11: error: 'a' was not declared in this scope
int t=a[1];
^