View Compilation Error

0_0_30466449_9152.cpp: In function 'int main()':
0_0_30466449_9152.cpp:63:64: error: 'dis' was not declared in this scope
         for(int i = 0; i <= n; i ++) pre[i] = i, G[i].clear(), dis[i] = 0;
                                                                ^