1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495 |
- import java.util.*;
- /***********************************************************
- * Oblig 3 - sekvensiell kode, INF2440 v2017.
- * Ifi, Uio, Arne Maus
- * for store verdier av n > 100 m, kjør (f.eks):
- * >java -Xmx16000m MultiRadix 1000000000
- ************************************************************/
- class MultiRadix{
- int n;
- int [] a;
- final static int NUM_BIT = 7; // alle tall 6-11 .. finn ut hvilken verdi som er best
-
- int [] radixMulti(int [] a) {
- long tt = System.nanoTime();
- // 1-5 digit radixSort of : a[]
- int max = a[0], numBit = 2, numDigits, n =a.length;
- int [] bit ;
-
- // a) finn max verdi i a[]
- //Timer ta = new Timer().start();
- for (int i = 1 ; i < n ; i++)
- if (a[i] > max) max = a[i];
- while (max >= (1L<<numBit) )numBit++; // antall binaere siffer i max
- //System.out.println("A: "+ta.end().prettyTime());
-
- // bestem antall bit i numBits sifre
- numDigits = Math.max(1, numBit/NUM_BIT);
- bit = new int[numDigits];
- int rest = (numBit%numDigits), sum =0;;
-
- // fordel bitene vi skal sortere paa jevnt
- for (int i = 0; i < bit.length; i++){
- bit[i] = numBit/numDigits;
- if ( rest-- > 0) bit[i]++;
- }
-
- int[] t=a, b = new int [n];
-
- for (int i =0; i < bit.length; i++) {
- radixSort( a,b,bit[i],sum ); // i-te siffer fra a[] til b[]
- sum += bit[i];
- // swap arrays (pointers only)
- t = a;
- a = b;
- b = t;
- }
- if (bit.length%2 != 0 ) {
- // et odde antall sifre, kopier innhold tilbake til original a[] (nå b)
- System.arraycopy (a,0,b,0,a.length);
- }
-
- return a;
- } // end radixMulti
-
- /** Sort a[] on one digit ; number of bits = maskLen, shiftet up 'shift' bits */
- void radixSort ( int [] a, int [] b, int maskLen, int shift){
- int acumVal = 0, j, n = a.length;
- int mask = (1<<maskLen) -1;
- int [] count = new int [mask+1];
-
- // b) count=the frequency of each radix value in a
- //Timer tb = new Timer().start();
- for (int i = 0; i < n; i++) {
- count[(a[i]>>> shift) & mask]++;
- }
- //System.out.println("B: "+tb.end().prettyTime());
-
- // c) Add up in 'count' - accumulated values
- //Timer tc = new Timer().start();
- for (int i = 0; i <= mask; i++) {
- j = count[i];
- count[i] = acumVal;
- acumVal += j;
- }
- //System.out.println("C: "+tc.end().prettyTime());
-
- // d) move numbers in sorted order a to b
- //Timer t = new Timer().start();
- for (int i = 0; i < n; i++) {
- b[count[(a[i]>>>shift) & mask]++] = a[i];
- }
- //t.end();
- //System.out.println("seq D: "+t.prettyTime());
-
- }// end radixSort
-
- void testSort(int [] a){
- for (int i = 0; i< a.length-1;i++) {
- if (a[i] > a[i+1]){
- System.out.println("SorteringsFEIL på plass: "+i +" a["+i+"]:"+a[i]+" > a["+(i+1)+"]:"+a[i+1]);
- return;
- }
- }
- }// end simple sorteingstest
- }// end SekvensiellRadix
|