Niuke real problem programming - Day9

Compile environment ：c++

1、 Wechat red packet description

During the Spring Festival, Xiao Ming received many red envelopes using wechat , Very happy . When checking the record of receiving red envelopes, I found , The amount of a red envelope appears more than half of the total number of red envelopes . Please help Xiao Ming find the amount of the red envelope . Write specific algorithm ideas and code implementation , The algorithm is required to be as efficient as possible .

Given an array of red envelopes gifts And its size n , Please return the requested amount of red envelope . If no amount exceeds half of the total , return 0.

Algorithmic thought ：

    The problem requires the algorithm to be as efficient as possible , Here we define a result structure , Red envelope amount meets 1≤gifti≤100000 Between , So declare an array of structures , Record N The amount and number of red envelopes , Then sort according to the number from small to large , When the largest element >n/2 when , Output the red packet size of this structure ; otherwise , Return to the unsatisfied condition 0.

The code part implements ：

2、 Jin Hua Zha

describe ：

 Two Sohu programmers worked an extra month , It's finally a holiday , So they decided to tie golden flowers for a happy holiday  .  The rules of the game ：  common 52 A common card , The face of the card is 2,3,4,5,6,7,8,9,10,J,Q,K,A One of , Increasing size , Four each ;  Each person grabs three cards . Two people compare the size of the three cards in their hands , The big man wins .  The rules for card types are as follows ： 1. Three cards are leopards  2. Three cards are connected into shunzi （A23 Not shunzi ） 3. There are only two pairs of cards   Leopard > Shunzi > Pairs > Ordinary brand type   When the card type is the same , Compare the value of the card type （ Such as AAA>KKK,QAK>534,QQ2>10104）  When both of them have no special card type , Compare the largest of the three cards in turn . The big man wins , If the biggest card is the same , Is the second largest , And so on （ Such as 37K>89Q）  If two people have the same face , It's a draw .

Algorithmic thought ：

    According to the title requirements , Do not list with complex conditions , But for different card types , Assign integer values of different sizes , To compare . First, judge the two input strings , When there is input , Convert the input to a length of 3 Integer array , take JQK Wait for cards to be converted into integer size ; Then judge the card type of the converted integer array , Leopard *100000、 Shunzi *10000、 Pairwise multiplication 1000、 Ordinary brand type is the largest brand *100. Compare the result size of two input strings , Print the corresponding output .

The code part implements ：

3、 First repeating character

describe

For a string , Please design an efficient algorithm , Find the first repeated character .

Given a string ( Not all letters )A And its length n. Please return the first repeated character . Ensure that there are duplicate characters in the string , The length of the string is less than or equal to 500.

Algorithmic thought ：

    Define a result set , Initialize to 0, Represents that this character has not appeared . Traversing every character in a string , When the characters are not out of date , Mark this character as true, When the same character is traversed for the second time , Just return the current character .

The code part implements ：