//最接近点对 一维情况package wkx;import java.io.IOException;import java.util.ArrayList;import java.util.Collections;import java.util.Iterator;import java.util.List;import java.util.Scanner;public class Test {private static int randomPartition(int[] data, int beg, int end) {int key = data[beg];while (beg < end) {while (beg < end && data[end] >= key)end--;data[beg] = data[end];while (beg < end && data[beg] <= key)beg++;data[end] = data[beg];}data[beg] = key;return beg;}private static int select(int[] data, int beg, int end, int k) {if (beg == end)// return data[beg];return beg;int mid = randomPartition(data, beg, end);int size = mid - beg + 1;if (k <= size)return select(data, beg, mid, k);elsereturn select(data, mid + 1, end, k - size);}private static int min(int a, int b) {if (a > b)return b;elsereturn a;}private static int min(int[] data, int beg, int end) {int min = Integer.MAX_VALUE;for (int i = beg; i <= end; i++) {if (data[i] < min)min = data[i];}return min;}private static int max(int[] data, int beg, int end) {int max = Integer.MIN_VALUE;for (int i = beg; i <= end; i++) {if (data[i] > max)max = data[i];}return max;}private static int CPair(int[] data, int beg, int end) {int len = end - beg + 1;if (len < 2)return Integer.MAX_VALUE;int mid = select(data, beg, end, len / 2);int dl = CPair(data, beg, mid);int dr = CPair(data, mid + 1, end);int p = min(data, mid + 1, end) - max(data, beg, mid);return min(min(dl, dr), p);}private static void print(List<Integer> l) {for (Iterator<Integer> it = l.iterator(); it.hasNext();)System.out.println(it.next());System.out.println();}public static void main(String[] args) throws IOException {Scanner in = new Scanner(System.in);List<Integer> l = new ArrayList<Integer>();int len = 0;while (in.hasNextInt()) {l.add(in.nextInt());len++;}Collections.sort(l);int[] data = new int[len];int t = 0;for (Iterator<Integer> it = l.iterator(); it.hasNext();)data[t++] = it.next().intValue();System.out.println(CPair(data, 0, len - 1));}}//最接近点对 二维package wkx;import java.io.IOException;import java.util.ArrayList;import java.util.Collections;import java.util.Iterator;import java.util.List;import java.util.Scanner;public class Test {// mergeprivate static void Merge(PointY[] Z, PointY[] Y, int beg, int mid, int end) {int l = beg;int r = mid + 1;int k = beg;while (l <= mid && r <= end) {if (Z[l].compareTo(Z[r]) == -1)Y[k++] = Z[l++];elseY[k++] = Z[r++];}while (l <= mid)Y[k++] = Z[l++];while (r <= end)Y[k++] = Z[r++];}// distanceprivate static double getDistance(Point a, Point b) {double dx = b.x - a.x;double dy = b.y - a.y;return Math.sqrt(Math.abs(dx * dx + dy * dy));}// printprivate static void printX(List<PointX> l) {for (Iterator<PointX> it = l.iterator(); it.hasNext();)System.out.println(it.next());System.out.println();}private static void printY(List<PointY> l) {for (Iterator<PointY> it = l.iterator(); it.hasNext();)System.out.println(it.next());System.out.println();}// pointprivate static class Point implements Cloneable{int x;int y;public String toString() {return "Point:x=" + this.x + " y=" + this.y;}}// pointXprivate static class PointX extends Point implements Comparable {public int compareTo(Object o) {PointX p = (PointX) o;if (p.x < this.x)return 1;else if (p.x == this.x)return 0;elsereturn -1;}}// PointYprivate static class PointY extends Point implements Comparable {int pos;public int compareTo(Object o) {PointY p = (PointY) o;if (p.y < this.y)return 1;else if (p.y == this.y)return 0;elsereturn -1;}}//min private static double min(double a, double b) {if (a > b)return b;elsereturn a;}//closestprivate static double closest(PointX[] X, PointY[] Y, PointY[] Z, int beg,int end, Point a, Point b) {// only two pointsif (end - beg == 1) {a.x = X[beg].x;a.y = X[beg].y;b.x = X[end].x;b.y = X[end].y;return getDistance(a, b);}// three Pointsif (end - beg == 2) {double d1 = getDistance(X[beg], X[beg + 1]);double d2 = getDistance(X[beg + 1], X[end]);double d3 = getDistance(X[beg], X[end]);if (d1 <= d2 && d1 <= d3) {a.x = X[beg].x;a.y = X[beg].y;b.x = X[beg + 1].x;b.y = X[beg + 1].y;return d1;} else if (d2 <= d1 && d2 <= d3) {a.x = X[beg + 1].x;a.y = X[beg + 1].y;b.x = X[end].x;b.y = X[end].y;return d2;} else {a.x = X[beg].x;a.y = X[beg].y;b.x = X[end].x;b.y = X[end].y;return d3;}}// more than threeint mid = (beg + end) / 2;int l = beg;int r = mid + 1;for (int i = beg; i <= end; i++) {if (Y[i].pos > mid)Z[r++] = Y[i];elseZ[l++] = Y[i];}double dl = closest(X, Z, Y, beg, mid, a, b);Point ar = new Point();Point br = new Point();double dr = closest(X, Z, Y, mid + 1, end, ar, br);if (dl > dr) {a.x = ar.x;b.x = br.x;a.y = ar.y;b.y = br.y;}double d = min(dl, dr);// rebuild YMerge(Z, Y, beg, mid, end);int k = beg;for (int i = beg; i <= end; i++) {if (Math.abs(Y[mid].x - Y[i].x) < d) {Z[k++]=Y[i];}}for(int i=beg;i<=end;i++){for(int j=i+1;j<k&&(Z[j].y-Z[i].y<d);j++){double dp=getDistance(Z[i],Z[j]);if(dp<d){d=dp;a.x=Z[i].x;b.x=Z[j].x;a.y=Z[i].y;b.y=Z[j].y;}}}// returnreturn d;}//mainpublic static void main(String[] args) throws IOException {// read ArrayScanner in = new Scanner(System.in);List<PointX> X = new ArrayList<PointX>();List<PointY> Y = new ArrayList<PointY>();int num = 0;while (in.hasNextInt()) {PointX pX = new PointX();PointY pY = new PointY();pX.x = pY.x = in.nextInt();pX.y = pY.y = in.nextInt();pY.pos = num++;X.add(pX);Y.add(pY);}//sortCollections.sort(X);Collections.sort(Y);printX(X);printY(Y);// copy to arrayPointX[] Xs = new PointX[num];PointY[] Ys = new PointY[num];Iterator<PointX> itX = X.iterator();Iterator<PointY> itY = Y.iterator();for (int i = 0; i < num; i++) {Xs[i] = itX.next();Ys[i] = itY.next();}PointY[] Zs = new PointY[num];Point a = new Point();Point b = new Point();double dis = closest(Xs, Ys, Zs, 0, num - 1, a, b);System.out.println(a);System.out.println(b);System.out.println("Point A:[" + a.x + "," + a.y + "]" + " Point B:["+ b.x + "," + b.y + "]" + " Distance:" + dis);/*Random rand=new Random(new Date().getTime());for(int i=1;i<=100;i++){System.out.println(rand.nextInt()+" "+rand.nextInt());}*/}}
