View Compilation Error

0_0_34540376_14133.cpp: In function 'int main()':
0_0_34540376_14133.cpp:52:56: error: 'k' was not declared in this scope
      dp[p * c[i] + q] = max(Q[head].zhi + p * w[i], dp[k * c[i] + q]);
                                                        ^