/in/foo.cc:9:1: error: expected initializer before 'int'
 int sum[100005];
 ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:15:9: error: 'sum' was not declared in this scope
  memset(sum,0,sizeof(sum));
         ^~~
/in/foo.cc:16:9: error: 'vis' was not declared in this scope
  memset(vis,false,sizeof(vis));
         ^~~