Java Data Structure-classic sorting highlights

Comparison of several sorting types !!

1. Bubble Sorting

Package COM. jzm. kindsofsort; public class bubblesort {/*** @ Param ARGs * Bubble Sorting */public static void bubblesort (comparable A []) {for (INT I = 1; I <. length; I ++) {for (Int J = 0; j <. length-1; j ++) {if (a [J]. compareto (A [J + 1])> 0) {comparable T = A [J]; A [J] = A [J + 1]; A [J + 1] = T ;}}} public static void main (string [] ARGs) {INTEGER [] pdata = {, 10, 6, 11,165}; bubblesort (pdata); system. out. println ("Final Result:"); For (INT I = 0; I <pdata. length; I ++) {system. out. print (pdata [I] + "");}}}

2. insertsort

Package COM. jzm. kindsofsort; public class insertionsort {// simple insertion sorting public static void insertsort (comparable [] data) {for (INT I = 1; I <data. length; I ++) {comparable TMP = data [I]; If (TMP. compareto (data [I-1]) <0) {Int J; For (j = I-1; j> = 0 & TMP. compareto (data [J]) <0; j --) {data [J + 1] = data [J];} data [J + 1] = TMP ;}}} public void display (comparable A []) {for (INT I = 0; I <. length; I ++) {system. out. print (A [I] + "") ;}} public static void main (string [] ARGs) {comparable A [] = {7,100, 1}; insertionsort = new insertionsort (); insertionsort. insertsort (a); insertionsort. display ();}}

3. quicksort

Package COM. jzm. kindsofsort; public class quicksort {// a public static void quicksort (integer [] A, int left, int right) {int I = left, j = right; int middle, strtemp; middle = A [(left + right)/2]; do {While (A [I] <middle) & (I <right) I ++; while (A [J]> middle) & (j> left) j --; if (I <= J) {strtemp = A [I]; A [I] = A [J]; A [J] = strtemp; I ++; j -- ;}} while (I <= J);/* system. out. println ("Left:" + Left + "Right:" + right); For (int t = 0; t <. length; t ++) system. out. print (A [T] + ""); system. out. println (""); */If (left <j) {quicksort (A, left, J);} If (Right> I) quicksort (A, I, right);} public static void main (string [] argv) {INTEGER [] pdata = {165,}; quicksort (pdata, 0, pdata. length-1); system. out. println ("Final Result:"); For (INT I = 0; I <pdata. length; I ++) {system. out. print (pdata [I] + "");}}}

4. quicksort2

Package COM. jzm. kindsofsort; public class quicksort2 {// General fast sorting, slow Private Static void swap (comparable A [], int I, Int J) {comparable T = A [I]; A [I] = A [J]; A [J] = T;} Private Static int partion (comparable [] A, int left, int right) {int I = left; int J = right + 1; Comparable x = A [left]; while (true) {While (A [++ I]. compareto (x) <0 & I <right); While (A [-- J]. compareto (x)> 0); if (I> = J) break; swap (A, I, j);} A [left] = A [J]; A [J] = x; return J;} public static comparable [] qsort (comparable [] A, int left, int right) {If (left <right) {int q = partion (A, left, right); // segment/* system. out. println ("Left:" + Left + "Right:" + right); For (int t = 0; t <. length; t ++) system. out. print (A [T] + ""); system. out. println (""); */qsort (A, left, q-1); qsort (A, q + 1, right);} return ;} public static void main (string [] ARGs) {comparable [] A = {11,165, 20,}; comparable [] T = qsort (A, 0, a. length-1); system. out. println ("Final Result:"); For (INT I = 0; I <t. length; I ++) {system. out. print (A [I] + "");}}}

5. shellsort

Package COM. jzm. kindsofsort; public class shellsort {// Hill sort public static void sort (INT [] A, int DK) {int I, j, temp; for (I = dk; I <. length; I ++) {if (a [I] <A [I-dk]) {temp = A [I]; A [I] = A [I-dk]; for (j = I; j> 0 & temp <A [J-1]; j = J-DK) {A [J] = A [J-1];} A [J] = temp ;}} public static void main (string ARGs []) {int [] A = {12,100, 12, 1,132}; int W = 1; while (W <=. length/5) {If (w % 2 = 0) {// improve efficiency O (N ^ 1.5) W = W + 1; system. out. println ("W");} Sort (A, W); W = W * 5 + 1;} For (INT I = 0; I <. length; I ++) system. out. print (A [I] + "");}}

6. simpleselectsort

Package COM. jzm. kindsofsort; public class simpleselectsort {// simple sort public static void sort (comparable [] data) {for (INT I = 0; I <data. length; I ++) {// record the current position int position = I; // locate the smallest number and use position to point to the smallest position for (Int J = I + 1; j <data. length; j ++) {If (data [position]. compareto (data [J])> 0) {position = J ;} // end if} // the minimum number of exchanges data [position] and the position comparable temp = data [I]; data [I] = data [position]; data [position] = temp;} // end for} // end sort public static void main (string [] ARGs) {// later than jdk1.5, the basic data types can be automatically packed. The comparable interface comparable [] C = {23,145,} has been implemented }; sort (c); For (comparable data: C) system. out. print (Data + "");}}

7. Sorting speed test

 

Package COM. jzm. kindsofsort; import Java. util. random; public class testspeed {/*** test the sorting speed. For large numbers, fast sorting speed is the fastest */Private Static final int maxnum = 50000; private Static Boolean issuccess (comparable A []) {for (INT I = 0; I <. length-2; I ++) {if (a [I]. compareto (A [I + 1])> 0) {system. out. println ("array A is not sorted in descending order"); Return false ;}} system. out. println ("detected"); Return true;} public static void main (string [] ARGs) {systemdate sysdate = new systemdate (); string strstarttime = sysdate. getthisdate (); debugruntime = new debugruntime (); random = new random (); integer a [] = new integer [maxnum]; for (INT I = 0; I <maxnum; I ++) {A [I] = random. nextint (maxnum);} // assign the initial value to the [] array // insertionsort. insertsort (a); // 24275 ms for simple insertion sorting. // simpleselectsort. sort (a); // simple sorting 34945 Ms. quicksort2.qsort (A, 0,. length-1); // 40 -- 52 Ms // quicksort. quicksort (A, 0,. length-1); // 30-50 ms // bubblesort. bubblesort (a); // 68079 -- 70356 Ms issuccess (a); string strstoptime = sysdate. getthisdate (); system. out. println ("program started at:" + strstarttime); system. out. println ("program ended at:" + strstoptime); debugruntime. executiontime (); // the running time in the background }}

8. Added test class

Package COM. jzm. kindsofsort; import Java. util. date; import Java. text. simpledateformat; import Java. text. parseexception; public class runtimec1c {public static void main (string [] Str) {systemdate sysdate = new systemdate (); string strstarttime = sysdate. getthisdate (); debugruntime = new debugruntime (); For (INT I = 0; I <5000; I ++) {for (Int J = 0; j <1000; j ++) {system. out. println ("I =" + I + ", j =" + J); // time-consuming I/O operations} string strstoptime = sysdate. getthisdate (); system. out. println ("program started at:" + strstarttime); system. out. println ("program ended at:" + strstoptime); debugruntime. executiontime (); // run time in the background} class debugruntime {private long starttime = 0; private long endtime = 0; Public debugruntime () {system. out. println ("begin .............................. "); this. setstarttime (system. currenttimemillis ();} public void executiontime () {This. setendtime (system. currenttimemillis (); system. out. println ("execution time:" + (this. getendtime ()-This. getstarttime () + "ms. ");} public void executiontime (string message) {This. setendtime (system. currenttimemillis (); system. out. println (Message + "execution time:" + (this. getendtime ()-This. getstarttime () + "ms. ");} private long getendtime () {return endtime;} private long getstarttime () {return starttime;} private void setendtime (long endtime) {This. endtime = endtime;} private void setstarttime (long starttime) {This. starttime = starttime ;}// a date operation class systemdate {public static systemdate = NULL; public date; Public String formattype = "yyyy/mm/DD-hh: mm: SS "; // Default Time Format: Public simpledateformat fmat; Public systemdate () {} static systemdate getinstance () {If (systemdate = NULL) systemdate = new systemdate (); return systemdate;} // returns the string of the current time. The default time format is formattype Public String getthisdate () {return getthisdate (formattype);} // returns the string of the input time, use the default time format formattype Public String getthisdate (date) {return getthisdate (formattype, date);} // return the string of the current time. The time format is the input parameter (string formattype) public String getthisdate (string formattype) {date = new date (); Return getthisdate (formattype, date) ;}// returns the string of the input time, the time format is input parameter (string formattype) Public String getthisdate (string formattype, date) {fmat = new simpledateformat (formattype); Return fmat. format (date) ;}// return time date, which is converted using the input time string. The input time format is the default time format formattype date getasstringdate (string strdate) throws parseexception {return getasstringdate (strdate, formattype);} // return time date, which is converted using the input time string. The input time format is string formattype date getasstringdate (string strdate, string formattype) throws parseexception {fmat = new simpledateformat (formattype); Return fmat. parse (strdate );}}

 

9. Conclusion: The sorting speed is about 5 million, which takes about 6 s.

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