Data structure-sort-quick row

Quick Sort

First, quickly sort the steps:

• First select the axis value
• Divides the content to be sorted into two parts, the left is less than or equal to the axis value, the right is greater than the axis value
• Then repeat the above steps to the left and right until the entire sequence is ordered
• Directly on the code here first write the divided code
• One division here is that the first number is the axis value, and we can use the last or the middle one.

• #include <iostream>#include<vector>using namespacestd;//an array without a staging unit v1inttemp1[]={ -, -, -, $,98, -, at, the, -, -};vector<int>v1 (Begin (Temp1), End (Temp1));//Print ArrayInlinevoidPRINTV (Constvector<int> &v) {     for(auto a:v) cout<<a<<" "; cout<<Endl;}//First Division//Quick Sort First DivisionintPartition (vector<int> &v,intFirstintend) {    intI=First ; intj=end;    Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  ";  while(i<j) { while(i<j&&v[i]<V[j]) {J--; cout<<"at this time i="<<i<<"at this time j="<<j<<Endl;} if(I&LT;J)//if i<j exchange ij{cout<<"Exchange"<<"  "; inttemp=V[j]; V[J]=V[i]; V[i]=temp; I++;            Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  "; } cout<<Endl;  while(i<j&&v[i]<=V[j]) {i++; cout<<"at this time i="<<i<<"at this time j="<<j<<Endl;} if(i<j) {cout<<"Exchange"<<"  "; inttemp=V[j]; V[J]=V[i]; V[i]=temp; J--;            Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  ";    }} printv (v); returni;}//Here we first call a division understanding how to divideintMainintargcChar*argv[]) {Partition (v1,0, V1.size ()-1); return 0;}

  Then run the analysis

　　

• First take 59 as the axis value, then because the left is smaller than 59, the right is greater than 59
• 59 and 28 comparison found 59 greater than 28 swap
• Continue traversing to the left after swapping. So i++, traversing to 98 found 59 small, exchanged
• Then the left side must be less than 59, but the right side is not sure, start traversing J
• J=8 found that 13 is less than 59 then swapped again, then the right must be greater than 59, left indeterminate, continue to traverse I
• I=7 59<83 Exchange
• This is i=j not meet i<j conditions jump out of the loop
• At this point 59 is the axis value, the left is less than 59 to the right is greater than

And then there's the complete, recursive, fast-line.

First on the code

#include <iostream>#include<vector>using namespacestd;//an array without a staging unit v1inttemp1[]={ -, -, -, $,98, -, at, the, -, -};vector<int>v1 (Begin (Temp1), End (Temp1));//Print ArrayInlinevoidPRINTV (Constvector<int> &4) {     for(auto a:v) cout<<a<<" "; cout<<Endl;}//Quick Sort One DivisionintPartition (vector<int> &v,intFirstintend) {    intI=First ; intj=end;    Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  ";  while(i<j) { while(i<j&&v[i]<V[j]) {J--; cout<<"at this time i="<<i<<"at this time j="<<j<<Endl;} if(I&LT;J)//if i<j exchange ij{cout<<"Exchange"<<"  "; inttemp=V[j]; V[J]=V[i]; V[i]=temp; I++;            Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  "; } cout<<Endl;  while(i<j&&v[i]<=V[j]) {i++; cout<<"at this time i="<<i<<"at this time j="<<j<<Endl;} if(i<j) {cout<<"Exchange"<<"  "; inttemp=V[j]; V[J]=V[i]; V[i]=temp; J--;            Printv (v); cout<<"at this time i="<<i<<"at this time j="<<j<<"  ";    }} printv (v); cout<<"once part ends"<<Endl; returni;}//Quick LinevoidQuickSort (vector<int> &v,intFirstintend) {    if(first<end) {        intpivot=Partition (v,first,end); QuickSort (V,first,pivot-1);; QuickSort (V,pivot+1, end); }}intMainintargcChar*argv[]) {QuickSort (v1,0, V1.size ()-1); return 0;}

• Let's take a look at the quicksort function, and when the partition function returns I,i is just 59 of the position
• We now take 59 as the dividing line, divided into the left and right sides, respectively, to continue to divide, until the number of each recursive First-end range =1 jumped
• Look at the following recursion the first time after the partition call ends, the argument behind Quicksort is the position of the v,,first,i-1 For example, the first recursion is v[0] to 59 minus 1.
• Then the back is 59+1 to V.end ();
• We run the program to see

• This is nonstop to the left left hand side of the recursion

• It's nonstop to the right right hand recursion. Recursion soon ended because the numbers on the right were few.

　　　　

　　　　

Data structure-sort-quick row