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  1. //
  2. //  main.cpp
  3. //  K nearest neighbors
  4. //
  5. //  Created by Himanshu on 18/08/21.
  6. //
  7.  
  8. #include <iostream>
  9. #include <vector>
  10. #include <algorithm>
  11. #include <math.h>
  12. using namespace std;
  13. int const N = 5;
  14.  
  15. bool cmp( const vector<float>& p,
  16.                const vector<float>& q ) {
  17.     return p[1] > q[1];
  18. }
  19.  
  20. void solve (int points[][2], int point[], int k) {
  21.     vector< vector<float> > minHeap;
  22.  
  23.     for (int i=0; i<N; i++) {
  24.         float d = sqrt((pow((point[0] - points[i][0]), 2)) + (pow((point[1] - points[i][1]), 2)));
  25.         float pos = i;
  26.         minHeap.push_back({pos, d});
  27.         push_heap(minHeap.begin(), minHeap.end(), &cmp);
  28.     }
  29.  
  30.     cout<<"K nearest neighbors:"<<endl;
  31.     for (int i=0; i<k; i++) {
  32.         vector<float> nearestPoints = minHeap.front();
  33.         pop_heap(minHeap.begin(), minHeap.end(), &cmp);
  34.         minHeap.pop_back();
  35.         cout<<nearestPoints[0]<<" - distance: "<<nearestPoints[1]<<endl;
  36.     }
  37.  
  38. }
  39.  
  40. int main () {
  41.     int points[N][2] = {{1, 1}, {3, 4}, {2, 3}, {7, 8}, {2, 5}};
  42.     int point[2] = {0, 0};
  43.     int k = 2;
  44.     solve(points, point, k);
  45.     return 0;
  46. }
  47.  
Success #stdin #stdout 0.01s 5512KB
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stdin
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Standard input is empty
stdout
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K nearest neighbors:
0 - distance: 1.41421
2 - distance: 3.60555
https://ideone.com/ksFPZf
language:
C++ 4.3.2 (gcc-4.3.2)
created:
3 years ago
visibility:
secret

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