View Compilation Error

0_0_19836702_21244.cpp: In member function 'int Trie::solve()':
0_0_19836702_21244.cpp:106:23: error: 'ac' was not declared in this scope
       dp[num][j | end[ac.next[k][t]]][next[k][t]] += dp[num ^ 1][j][k];
                       ^