knn improved

Vector/vector.c

@@ -25,6 +25,8 @@ void deleteVector(Vector v){
 
 
 void printVector(Vector v){
+ if(v==NULL)
+ return;
  printf("\n[");
  for(int i=0;i<d;i++){
  printf(" %f",v->coords[i]);

hashTable/hashTableList/hashTableList.c

@@ -119,64 +119,110 @@ void swapVectors(Vector *xp, Vector *yp)
  *yp = temp;
 }
 
-// A function to implement bubble sort
-void bubbleSort(double arr[], Vector *nearest, int n)
-{
- for (int i = 0; i < n - 1; i++){
- for (int j = 0; j < n - i - 1; j++){
- if (arr[j] < arr[j + 1]){
- swapDoubles(&arr[j], &arr[j + 1]);
- swapVectors(&nearest[j], &nearest[j + 1]);
- }
+// void bubbleSort(double arr[], Vector *nearest, int n)
+// {
+// for (int i = 0; i < n - 1; i++){
+// for (int j = 0; j < n - i - 1; j++){
+// if (arr[j] < arr[j + 1]){
+// swapDoubles(&arr[j], &arr[j + 1]);
+// swapVectors(&nearest[j], &nearest[j + 1]);
+// }
+// }
+// }
+// }
+
+
+// function to find the partition position
+int partition(double arr[], Vector *nearest, int low, int high){
+ double pivot = arr[high];
+ int i = (low - 1);
+ for (int j = low; j < high; j++) {
+ if (arr[j] >= pivot) {
+
+ i++;
+
+ swapDoubles(&arr[i], &arr[j]);
+ swapVectors(&nearest[i], &nearest[j]);
  }
  }
 
+ swapDoubles(&arr[i + 1], &arr[high]);
+ swapVectors(&nearest[i + 1], &nearest[high]);
+
+ return (i + 1);
+}
+
+void quickSort(double arr[], Vector *nearest, int low, int high){
+ if (low < high) {
+
+ int pi = partition(arr, nearest, low, high);
+
+ quickSort(arr,nearest, low, pi - 1);
+
+ quickSort(arr, nearest, pi + 1, high);
+ }
+}
+
+int binarySearch(double arr[], int l, int r, double x){
+ if (r >= l){
+ int mid = l + (r - l) / 2;
+ if (arr[mid] == x)
+ return mid;
+
+ if (arr[mid] < x)
+ return binarySearch(arr, l, mid - 1, x);
+
+ return binarySearch(arr, mid + 1, r, x);
+ }
+
+ return -1;
 }
 
 void listFindKNearestNeighbors(List list,Vector q,Vector *nearest,double *nearestDist,int d,int k){
  if(list==NULL){ return;}
  List temp=list;
+ int filled=0;
  while(temp!=NULL){
  int flag = 1;
  int eq = 0;
+ int added=0;
  double dist = distance_metric(temp->v,q,d);
 
  printf("---------------------------------------------------\n");
  printf("Vector:\n");
  printVector(temp->v);
  printf("WITH DISTANCE = %f\n", dist);
  printf("---------------------------------------------------\n");
- for (int i = 0; i < k; i++){
- if(nearestDist[i]<0){
- flag=0;
- for (int i = 0; i < k; i++){
- if (nearest[i] != NULL && compareVectors(nearest[i], temp->v))
- eq = 1;
- }
- if (eq)
- break;
- nearestDist[i]=dist;
- nearest[i]=temp->v;
- break;
- }
+
+ int index=binarySearch(nearestDist,0,k-1,dist);
+ if(index!=-1 && nearest[index] != NULL && compareVectors(nearest[index], temp->v)){
+ eq = 1;
  }
-
- if (flag){
+ if (eq){
+ temp = temp->next;
+ continue;
+ } 
+ if(!filled)
  for (int i = 0; i < k; i++){
- if(dist<nearestDist[i]){
- for (int i = 0; i < k; i++){
- if (nearest[i] != NULL && compareVectors(nearest[i], temp->v))
- eq=1;
- }
- if(eq) break;
-
- nearestDist[i] = dist;
- nearest[i] = temp->v;
+ if(nearestDist[i]<0){
+ flag=0;
+ added=1;
+ nearestDist[i]=dist;
+ nearest[i]=temp->v;
  break;
  }
  }
+
+ if (flag){
+ filled=1;
+ if(dist<nearestDist[0]){
+ added = 1;
+ nearestDist[0] = dist;
+ nearest[0] = temp->v;
+ }
  }
- bubbleSort(nearestDist,nearest,k);
+ if(added)
+ quickSort(nearestDist, nearest,0, k-1);
  temp = temp->next;
  } 
 }