Main.cc: In function ‘int main()’: Main.cc:29:20: error: invalid types ‘int[int]’ for array subscript time+=(n-i+1)*n[i]; ^ Main.cc:4:10: warning: unused variable ‘k’ [-Wunused-variable] int i,n,k=0,n1[101]={0},n2[101]={0}; ^