[Written test programming questions] Day3. (Find the longest continuous number string 69385 in the string) and (23271 the number that appears more than half of the time in the array)

About the author: Hello everyone, I am Weiyang;

Blog Homepage: Weiyang.303

Series of Columns: Written Examination Training Programming Questions

Daily sentence: There is only one time in a person's life to make a difference, and that is now! ! ! !

Article directory

​edit 

foreword

1. Find the longest continuous number string 69385 in the string

topic description

topic analysis

Code

Summarize

---

 

foreword

1. Find the longest continuous number string 69385 in the string

topic description

Given an array of length n, there is a number in the array that occurs more than half of the length of the array, please find this number. For example: Enter an array [1,2,3,2,2,2,5,4,2] of length 9. Since the number 2 appears 5 times in the array, which exceeds half the length of the array, 2 is output.

Enter a description:

保证数组输入非空，且保证有解

Example:

---

---

Topic analysis:

 Problem-solving ideas:

After seeing this question, there are two main ideas:

Idea 1 (common and simple)

1. First sort our array (no limit to ascending and descending relations);
2. Find the letter X in the middle;
3. Then traverse the array; (see how many times this array appears)

Idea 2 (idea of ​​mode elimination)

General idea description:

If the two numbers are not equal, cancel the two numbers;

In the worst case, one mode and one non-mode will be eliminated each time;

Then if there is a mode number, the last number left must be the mode number; but if it is not purely in the mode number, it must not be;

(So ​​this place still has to traverse the array to determine whether the last number is a majority)

---

Code

Idea one:

---

Idea 2:

---

Summarize