# Data structures Interview Questions

“Given a singly linked list, how can you find if there is a loop in the list?” |

“Binary tree with parent pointers, given two nodes find common ancestor.” |

“Write a code for finding a certain element in an unsorted array assuming element definitely exists. How can we improve the efficiency?” |

“How would you print last n elements of a linked list, n being small compared to size of linked list?” |

“Given an array of integers, all but one of which appears an even number of times, find the one integer which appears an odd number of times.” |

1 of 1 found helpful |

“Give me 5 different ways of finding the median (middle element) of a linked list. For the sake of simplicity, assume the list has odd number of ints. Also mention the runtime for each. Follow up...” |

“How would you implement a stack to achieve constant time for "push", "pop" and "find mininum" operations?” |

“1. Find common elements between two arrays of integers. 2. Find cycles in a graph. 3. Efficiently find duplicate elements in an array of numbers with bounded entries (for example, elements are...” |

“Create a Queue using two Stacks.” |

“3. Trees (binary and otherwise) form the basis of many common data structures. Please describe some of these data structures and when they might be used.” |

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