यह एक सरणी में बिंदुओं के निकटतम युग्म को खोजने का कार्यक्रम है।
एल्गोरिदम
निकटतम बिंदु के बीच की दूरी के लिए
डबल डेटाटाइप के लिएBegin Declare function Closest_dist_Spoint(poi stp[], int s, double dist, poi &pnt1, poi &pnt2) to the double datatype. Declare Minimum to the double datatype. Initialize Minimum = dist. for (int i = 0; i < s; ++i) for (int j = i+1; j < s && (stp[j].poi2 - stp[i].poi2) < Minimum; ++j) if (Distance(stp[i],stp[j]) < Minimum) then Minimum = Distance(stp[i], stp[j]). pnt1.poi1 = stp[i].poi1, pnt1.poi2 = stp[i].poi2. pnt2.poi1 = stp[j].poi1, pnt2.poi2 = stp[j].poi2. Return Minimum. End.
सबसे छोटी दूरी की गणना करने के लिए -
डबल डेटाटाइप के लिएBegin Declare function Closest_dist(poi P[], poi stp[], int n, poi &pnt1, poi &pnt2) to the double datatype. Declare static object pt1, pt2, pt3, pt4 of poi structure. if (n <= 3) then return S_Distance(P, n, pt1, pt2). Declare medium to the integer datatype. Initialize midium = n/2. Declare object mediumPoint of poi structure. Initialize midiumPoint = P[midium]. Declare D_Left to the double datatype. Initialize D _Left = Closest_dist(P, stp, midium, pt1, pt2). Declare D_Right to the double datatype. Initialize D_Right = Closest_dist(P + midium, stp, n-midium, pt3, pt4). if(D_Left < D_Right) then pnt1.poi1 = pt1.poi1; pnt1.poi2 = pt1.poi2. pnt2.poi1 = pt2.poi1; pnt2.poi2 = pt2.poi2. else pnt1.poi1 = pt3.poi1; pnt1.poi2 = pt3.poi2; pnt2.poi1 = pt4.poi1; pnt2.poi2 = pt4.poi2; Declare min_dist to the double datatype. Initialize min_dist = Minimum(D_Left, D_Right). Declare j to the integer datatype. initialize j = 0. for (int i = 0; i < n; i++) if (abs(P[i].poi1 - midiumPoint.poi1) < min_dist) then stp[j++] = P[i]. Declare min_dist_strip, F_Min to the double datatype. Initalize min_dist_strip = Closest_dist_Spoint(stp, j, min_dist, pt1, pt2). Initialize F_Min = min_dist. if(min_dist_strip < min_dist) then pnt1.poi1 = pt1.poi1; pnt1.poi2 = pt1.poi2; pnt2.poi1 = pt2.poi1; pnt2.poi2 = pt2.poi2; F_Min = min_dist_strip; Return F_Min. End.
उदाहरण
#include <iostream> #include <cfloat> #include <cstdlib> #include <cmath> using namespace std; struct poi { double poi1, poi2; }; inline int Comp_poi1(const void* x, const void* b) { poi *p1 = (poi *)x, *pnt2 = (poi *)b; return (p1->poi1 - pnt2->poi1); } inline int Comp_poi2(const void* x, const void* y) { poi *pnt1 = (poi *)x, *pnt2 = (poi *)y; return (pnt1->poi2 - pnt2->poi2); } inline double Distance(poi pnt1, poi pnt2) { // Calculate the distance between two points return sqrt( (pnt1.poi1 - pnt2.poi1)*(pnt1.poi1 - pnt2.poi1) + (pnt1.poi2 - pnt2.poi2)*(pnt1.poi2 - pnt2.poi2) ); } double S_Distance(poi P[], int n, poi &pnt1, poi &pnt2) { double min = DBL_MAX; for (int i = 0; i < n; ++i) for (int j = i+1; j < n; ++j) if (Distance(P[i], P[j]) < min) { min = Distance(P[i], P[j]); pnt1.poi1 = P[i].poi1, pnt1.poi2 = P[i].poi2; pnt2.poi1 = P[j].poi1, pnt2.poi2 = P[j].poi2; } return min; } inline double Minimum(double poi1, double poi2) { // Find minimum between two values return (poi1 < poi2)? poi1 : poi2; } double Closest_dist_Spoint(poi stp[], int s, double dist, poi &pnt1, poi &pnt2) { // Calculate distance beween the closest points double Minimum = dist; // Initialize the minimum distance as dist qsort(stp, s, sizeof(poi), Comp_poi2); for (int i = 0; i < s; ++i) for (int j = i+1; j < s && (stp[j].poi2 - stp[i].poi2) < Minimum; ++j) if (Distance(stp[i],stp[j]) < Minimum) { Minimum = Distance(stp[i], stp[j]); pnt1.poi1 = stp[i].poi1, pnt1.poi2 = stp[i].poi2; pnt2.poi1 = stp[j].poi1, pnt2.poi2 = stp[j].poi2; } return Minimum; } double Closest_dist(poi P[], poi stp[], int n, poi &pnt1, poi &pnt2) { // Calculate smallest distance. static poi pt1, pt2, pt3, pt4; if (n <= 3) return S_Distance(P, n, pt1, pt2); int medium = n/2; // Calculate the mid point poi mediumPoint = P[medium]; double D_Left = Closest_dist(P, stp, medium, pt1, pt2); // D_Left: left of medium point double D_Right = Closest_dist(P + medium, stp, n-medium, pt3, pt4); // D_Right: right side of the medium point if(D_Left < D_Right) { pnt1.poi1 = pt1.poi1; pnt1.poi2 = pt1.poi2; // Store the pair that has smaller distance pnt2.poi1 = pt2.poi1; pnt2.poi2 = pt2.poi2; } else { pnt1.poi1 = pt3.poi1; pnt1.poi2 = pt3.poi2; pnt2.poi1 = pt4.poi1; pnt2.poi2 = pt4.poi2; } double min_dist = Minimum(D_Left, D_Right); int j = 0; for (int i = 0; i < n; i++) if (abs(P[i].poi1 - mediumPoint.poi1) < min_dist) stp[j++] = P[i]; double min_dist_strip = Closest_dist_Spoint(stp, j, min_dist, pt1, pt2); double F_Min = min_dist; if(min_dist_strip < min_dist) { pnt1.poi1 = pt1.poi1; pnt1.poi2 = pt1.poi2; pnt2.poi1 = pt2.poi1; pnt2.poi2 = pt2.poi2; F_Min = min_dist_strip; } return F_Min; } int main() { poi P[] = {{4, 1}, {15, 20}, {30, 40}, {8, 4}, {13, 11}, {5, 6}}; poi pnt1 = {DBL_MAX, DBL_MAX}, pnt2 = {DBL_MAX, DBL_MAX}; // Closest pair of points in array int n = sizeof(P) / sizeof(P[0]); qsort(P, n, sizeof(poi), Comp_poi1); poi *stp = new poi[n]; cout << "The closest distance of point in array is: " << Closest_dist(P, stp, n, pnt1, pnt2) << endl; cout << "The closest pair of point in array: (" << pnt1.poi1 << "," << pnt1.poi2 << ") and (" << pnt2.poi1 << "," << pnt2.poi2 << ")" << endl; delete[] stp; return 0; }
आउटपुट
The closest distance of point in array is: 3.60555 The closest pair of point in array: (13,11) and (15,20)