hello guys i need to sort some elements of integer in an integer array and need to store the index of the sorted list
assume if the elements in array are
x[]= {10,20,40,70,80,50,30};
i need to get the index of the sorted order say in this case i need to get 4,3,5,2,6,0 (ascending) (array x starting from 0)
A simple way (not algorithmically clever) would be to make a new list (or array) of objects from the existing list that contains the value and the index:
class ValueAndIndex implements Comparable<ValueAndIndex> {
final int value;
final int index;
ValueAndIndex(int value, int index) {
this.value = value;
this.index = index;
}
@Override public int compareTo(ValueAndIndex other) {
// compare on value;
if (this.value < other.value) {
return -1;
} else if (this.value > other.value) {
return 1;
} else {
return 0;
}
}
}
Now, create instances of this class in a list:
List<ValueAndIndex> secondaryList = new ArrayList<ValueAndIndex>(x.length);
for (int i = 0; i < x.length; ++i) {
secondaryList.add(new ValueAndIndex(x[i], i));
}
Sort this list:
Collections.sort(secondaryList);
Now, the indices are still in this list:
int [] indexesInSortedOrder = new int[x.length];
for (int i = 0; i < secondaryList.size(); ++i) {
indexesInSortedOrder[i] = secondaryList.get(i).index;
}
System.out.println(Arrays.toString(indexesInSortedOrder));
Possible solution
//sort the array intio a new array
y[] = x;
Arrays.sort(y); //sort ascending
//final array of indexes
int index_array[] = new int[7];
//iteretate on x arrat
for(int i=0; i<7; i++)
//search the position of a value of the original x array into the sorted y array, store the position in the index array
index_array[i] = arrays.binarySearch(x,y[i]);
you can create an array
y[] = {0,1,2,3,4,5,6};
And ith any sorting algorithm, when you switching moving two elements in array x, do the same in array y
One way to do (what I understand) you need:
n of the original array.R and initialize its elements with 0 . . n-1RExample run:
Copied Result
Array
------------------
1. 2-3-1 0-1-2
2. 2-1-3 0-2-1
3. 1-2-3 2-0-1
public Map sortDecendingDFSGlobal() {
Map<String, Object> multiValues = new HashMap<String, Object>();
double[] dfs = this.global_dfs;
int[] index = new int[dfs.length];
for (int i = 0; i < dfs.length; i++) {
index[i] = i;//for required indexing
}
for (int i = 0; i < dfs.length; i++) {
//sorting dfsglobal in decending order
double temp = dfs[i];
double swap = dfs[i];
int swapIndex = i;
//keeping track of changing indexing during sorting of dfsglobal
int indStart = index[i];
int indSwap = index[i];
int number = i;
for (int j = i; j < dfs.length; j++) {
if (temp < dfs[j]) {
temp = dfs[j];
swapIndex = j;
indSwap = index[j];
number = j;
}
}
dfs[i] = temp;
dfs[swapIndex] = swap;
index[i] = indSwap;
index[number] = indStart;
}
//again sorting the index matrix for exact indexing
for (int i = 0; i < index.length - 1; i++) {
for(int j = i; j < index.length - 1; j++ )
{
if(dfs[j] == dfs[j + 1] && index[j] > index[j + 1])
{
int temp = index[j];
index[j] = index[j+1];
index[j + 1] = temp;
}
}
}
this.sortedDFS = dfs;
this.arrIndex = index;
multiValues.put("sorted", dfs);
multiValues.put("index", index);
return multiValues;
} //SortedDecendingDFSGlobal()
