View Compilation Error

0_0_25578377_27393.cpp: In function 'void update(ll, ll)':
0_0_25578377_27393.cpp:6:42: error: 'C' was not declared in this scope
 void update(ll x,ll val){ for( ; x<=maxn;C[x]+=val,x+=lowbit(x)); }
                                          ^
0_0_25578377_27393.cpp: In function 'll getsum(ll)':
0_0_25578377_27393.cpp:7:43: error: 'C' was not declared in this scope
 ll getsum(ll x){ ll ret=0; for(; x>0;ret+=C[x] ,x-=lowbit(x));return ret; }
                                           ^
0_0_25578377_27393.cpp: In function 'int main()':
0_0_25578377_27393.cpp:19:34: error: expected primary-expression before '=' token
         ll n,C[maxn]={0},a[maxn];={0};
                                  ^