随笔分类 - PAT(甲级)
摘要:In computer science, a heap is a specialized tree based data structure that satisfies the heap property: if P is a parent node of C, then the key (the
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摘要:This is a problem given in the Graduate Entrance Exam in 2018: Which of the following is NOT a topological order obtained from the given directed grap
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摘要:The task of this problem is simple: insert a sequence of distinct positive integers into a hash table first. Then try to find another sequence of inte
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摘要:Given N integers, you are supposed to find the smallest positive integer that is NOT in the given list. Input Specification: Each input file contains
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摘要:The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. A binary search tree (BST) i
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摘要:A clique is a subset of vertices of an undirected graph such that every two distinct vertices in the clique are adjacent. A maximal clique is a clique
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摘要:After each PAT, the PAT Center will announce the ranking of institutions based on their students' performances. Now you are asked to generate the rank
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摘要:Look and say sequence is a sequence of integers as the following: D, D1, D111, D113, D11231, D112213111, ... where D is in [0, 9] except 1. The (n+1)s
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摘要:Unlike in nowadays, the way that boys and girls expressing their feelings of love was quite subtle in the early years. When a boy A had a crush on a g
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摘要:Suppose that all the keys in a binary tree are distinct positive integers. Given the preorder and inorder traversal sequences, you are supposed to out
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摘要:For a student taking the online course "Data Structures" on China University MOOC (http://www.icourse163.org/), to be qualified for a certificate, he/
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摘要:There is a kind of balanced binary search tree named red black tree in the data structure. It has the following 5 properties: (1) Every node is either
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摘要:Consider a positive integer N written in standard notation with k+1 digits ai as ak ⋯a1a0 with 0≤ai 0. Then N is palindromic if and only if ai =ak−
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摘要:A vertex cover of a graph is a set of vertices such that each edge of the graph is incident to at least one vertex of the set. Now given a graph with
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摘要:Given a singly linked list, you are supposed to rearrange its elements so that all the negative values appear before all of the non negatives, and all
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摘要:Cutting an integer means to cut a K digits lone integer Z into two integers of (K/2) digits long integers A and B. For example, after cutting Z = 1673
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摘要:In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijing su
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摘要:Given a syntax tree (binary), you are supposed to output the corresponding infix expression, with parentheses reflecting the precedences of the operat
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摘要:Recommendation system predicts the preference that a user would give to an item. Now you are asked to program a very simple recommendation system that
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摘要:The "eight queens puzzle" is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other. Thus, a solutio
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