【本文链接】
http://www.cnblogs.com/hellogiser/p/ali-2015-questions.html
1. 写一个函数，输入一个二叉树，树中每个节点存放了一个整数值，函数返回这棵二叉树中相差最大的两个节点间的差值绝对值。请注意程序效率。
C++ Code
|
1
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 |
/*
version: 1.0 author: hellogiser blog: http://www.cnblogs.com/hellogiser date: 2014/9/14 */ struct BinaryTreeNode { int value; BinaryTreeNode *left; BinaryTreeNode *right; }; void PreOrder(BinaryTreeNode *root, int &max, int &min) { if (root == NULL) return; if (max < root->value) { max = root->value; } if (min > root->value) { min = root->value; } PreOrder(root->left, max, min); PreOrder(root->right, max, min); } int MaxDiff(BinaryTreeNode *root) { if (root == NULL) return INT_MIN; int min, max; min = max = root->value; PreOrder(root, max, min); return max - min; } |
2 给定一个query和一个text，均由小写字母组成。要求在text中找出以同样的顺序连续出现在query中的最长连续字母序列的长度。例如， query为“acbac”，text为“acaccbabb”，那么text中的“cba”为最长的连续出现在query中的字母序列，因此，返回结果应该为其长度3。请注意程序效率。
C++ Code
|
1
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 |
/*
version: 1.0 author: hellogiser blog: http://www.cnblogs.com/hellogiser date: 2014/9/14 */ #include "stdafx.h" #include "iostream" using namespace std; void output_array(int **a, int len1, int len2) { int i, j; for(i = 0; i <= len1; i++) { for(j = 0; j <= len2; j++) { cout << a[i][j] << " "; } cout << endl; } cout << endl; } int findstring(char *query, char *text) { if(NULL == query || NULL == text) { return -1; } int len1 = strlen(text); int len2 = strlen(query); int **arrays = new int *[len1 + 1]; int i, j; for(i = 0; i <= len1; ++i) arrays[i] = new int[len2 + 1](); int max = 0; for(i = 1; i <= len1; i++) { for(j = 1; j <= len2; j++) { if(text[i - 1] == query[j - 1]) arrays[i][j] = arrays[i - 1][j - 1] + 1; else arrays[i][j] = 0; // get max of arrays if(max < arrays[i][j]) { max = arrays[i][j]; } } } output_array(arrays, len1, len2); for(i = 0; i <= len1; i++) delete [] arrays[i]; delete [] arrays; return max; } void test_default(char *query, char *text) { cout << findstring(query, text) << endl; } void test_case1() { char *query = "acbac"; char *text = "acaccbabb"; test_default(query, text); // 3 cba } void test_main() { test_case1(); } int main() { test_main(); return 0; } |
【参考】