0_0_38175933_15119.cpp: In function 'int main()': 0_0_38175933_15119.cpp:143:3: error: 'vis' was not declared in this scope vis[i]=head[i]=0; ^ 0_0_38175933_15119.cpp:143:10: error: 'head' was not declared in this scope vis[i]=head[i]=0; ^