Ich schrieb eine Implementierung der Inversion-Zählung. Dies ist eine Aufgabe, die in einem Online-Kurs durchgeführt wird. Aber die Eingabe, die ich bekomme, ist nicht korrekt und entsprechend dem, was ich habe, hat das Programm eine korrekte Syntax. Ich habe nicht nur wissen, war ich ging schief Das folgende Programm ist meine ImplementierungProbleme mit Inversion-Zählung Algorithmus
import java.io.*;
class CountInversions {
//Create an array of length 1 and keep expanding as data comes in
private int elements[];
private int checker = 0;
public CountInversions() {
elements = new int[1];
checker = 0;
}
private boolean isFull() {
return checker == elements.length;
}
public int[] getElements() {
return elements;
}
public void push(int value) {
if (isFull()) {
int newElements[] = new int[elements.length * 2];
System.arraycopy(elements, 0, newElements, 0, elements.length);
elements = newElements;
}
elements[checker++] = value;
}
public void readInputElements() throws IOException {
//Read input from file and until the very last input
try {
File f = new File("IntegerArray.txt");
FileReader fReader = new FileReader(f);
BufferedReader br = new BufferedReader(fReader);
String stringln;
while ((stringln = br.readLine()) != null) {
push(Integer.parseInt(stringln));
}
System.out.println(elements.length);
fReader.close();
} catch (Exception e) {//Catch exception if any
System.err.println("Error: " + e.getMessage());
} finally {
// in.close
}
}
//Perform the count inversion algorithm
public int countInversion(int array[],int length){
int x,y,z;
int mid = array.length/2 ;
int k;
if (length == 1){
return 0;
}else{
//count Leftinversion and count Rightinversion respectively
int left[] = new int[mid];
int right[] = new int[array.length - mid];
for(k = 0; k < left.length;k++){
left[k] = array[k];
}
for(k = 0 ;k < right.length;k++){
right[k] = array[mid + k];
}
x = countInversion(left, left.length);
y = countInversion(right, right.length);
int result[] = new int[array.length];
z = mergeAndCount(left,right,result);
//count splitInversion
return x + y + z;
}
}
private int mergeAndCount(int[] left, int[] right, int[] result) {
int count = 0;
int i = 0, j = 0, k = 0;
int m = left.length, n = right.length;
while(i < m && j < n){
if(left[i] < right[j]){
result[k++] = left[i++];
}else{
result[k++] = right[j++];
count += left.length - i;
}
}
if(i < m){
for (int p = i ;p < m ;p++){
result[k++] = left[p];
}
}
if(j < n){
for (int p = j ;p < n ;p++){
result[k++] = right[p];
}
}
return count;
}
}
class MainApp{
public static void main(String args[]){
int count = 0;
CountInversions cIn = new CountInversions();
try {
cIn.readInputElements();
count = cIn.countInversion(cIn.getElements(),cIn.getElements().length);
System.out.println("Number of Inversios: " + count);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
Was für eine Zählung Inversion ist? –
@OliCharlesworth Inversion zählen, scheint es. –
@OliCharlesworth, https://www.google.co.uk/webhp?sourceid=chrome-instant&ix=sea&ie=UTF-8&ion=1#hl=de&safe=off&output=search&sclient=psy-ab&q=count%20inversion&oq=&aq= & aqi = & aql = & gs_l = & pbx = 1 & fp = 2dc54432a6a9a210 & ix = meer & ion = 1 & bav = on.2, oder.r_gc.r_pw.r_cp.r_qf., cf.osb & biw = 1366 & bih = 667 –