View Compilation Error

0_0_37633783_14205.cpp: In function 'void solve()':
0_0_37633783_14205.cpp:14:5: error: 'vector' was not declared in this scope
     vector<int> a(20);
     ^
0_0_37633783_14205.cpp:5:13: error: expected primary-expression before 'long'
 #define int long long
             ^
0_0_37633783_14205.cpp:14:12: note: in expansion of macro 'int'
     vector<int> a(20);
            ^
0_0_37633783_14205.cpp:18:9: error: 'a' was not declared in this scope
         a[++tot] = n % 10;
         ^
0_0_37633783_14205.cpp:27:31: error: 'a' was not declared in this scope
         ans += dp[i - 1][2] * a[i];
                               ^