排序可视化
SelectionSort
选择排序很简单，所有的排序算法在前面的博客都有讲解：
https://www.jianshu.com/p/7fbf8671c742
选择排序很简单，遍历所有元素，查看一下他们的之后最小的元素和当前元素交换即可。模板函数使用上面的swing模板。为了更清楚显示出排序的过程，可以用不同颜色代表排好序和未排好序的。
int w = canvasWidth / data.N();
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.LightBlue);
for (int i = 0; i < data.N(); i++) {
if (i < data.orderIndex) {
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.Red);
} else {
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.Grey);
}
if (i == data.currentIndex) {
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.Indigo);
}
if (i == data.currentComperent) {
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.LightBlue);
}
AlgorithmHelper.fillRectangle(graphics2D, i * w, canvasHeight - data.get(i), w - 1, data.get(i));
}
}
Frame的画图函数主要构成部分，其余的都是模板，为了抽象性，所以把selection的数据集中起来形成一个新的类，包括了生成数据等等。
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public class SelectionSortData {
private int[] numbers;
public int orderIndex = -1;
public int currentIndex = -1;
public int currentComperent = -1;
public SelectionSortData(int N, int randomBound) {
numbers = new int[N];
for (int i = 0; i < N; i++) {
numbers[i] = (int) (Math.random() * randomBound) + 1;
//System.out.println(numbers[i]);
}
}
public void setData(int orderIndex, int currentComperent, int currentIndex){
this.currentIndex = currentIndex;
this.currentComperent = currentComperent;
this.orderIndex = orderIndex;
}
public int N(){
return numbers.length;
}
public int get(int index){
if (index < 0 || index >= numbers.length){
throw new IllegalArgumentException("index is illgel!");
}
return numbers[index];
}
public void swap(int i, int j){
int t = numbers[i];
numbers[i] = numbers[j];
numbers[j] = t;
}
}
在这个数据类里面有三个属性，分别是已经排好序的索引，当前最小值，当前正在比较的索引。在渲染过程中需要改变就是这几个颜色了。所以动态的效果主要来源就是通过改变着几个值即可。
private void run() {
data.setData(0,-1,-1);
frame.render(data);
AlgorithmHelper.pause(DELAY);
for (int i = 0; i < data.N(); i++) {
int midIndex = i;
data.setData(i, -1, midIndex);
frame.render(data);
AlgorithmHelper.pause(DELAY);
for (int j = i+1; j < data.N(); j++) {
data.setData(i, j, midIndex);
frame.render(data);
AlgorithmHelper.pause(DELAY);
if (data.get(j) < data.get(midIndex)){
midIndex = j;
data.setData(i, j, midIndex);
frame.render(data);
AlgorithmHelper.pause(DELAY);
}
}
data.swap(i, midIndex);
data.setData(i+1, -1, -1);
frame.render(data);
AlgorithmHelper.pause(DELAY);
}
data.setData(data.N(), -1,-1);
frame.render(data);
AlgorithmHelper.pause(DELAY);
}
查看一下效果：
InsertionSort
插入排序也很简单，没有涉及到递归操作等等。每遍历一个元素，看看这个元素和之前比较过的位置是在那里，像打牌的时候插排一样。和之前的查找一样，已经排好序的位置就直接用红色表示，当前对比位置用蓝色表示。首先是画图paintComponent：
int w = canvasWidth / data.N();
for (int i = 0; i < data.N(); i++) {
if (i < data.orderIndex){
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.Red );
}else {
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.Grey);
}
if (i == data.currentIndex){
AlgorithmHelper.setColor(graphics2D, AlgorithmHelper.LightBlue);
}
AlgorithmHelper.fillRectangle(graphics2D, i * w, canvasHeight - data.get(i), w - 1, data.get(i));
}
}
和上面的选择排序差不多。
private void run() {
setData(-1, -1);
for (int i = 0; i < data.N(); i++) {
setData(i, i);
for (int j = i; j > 0 && data.get(j) < data.get(j - 1); j--) {
data.swap(j, j - 1);
setData(i+1, j-1);
}
setData(i, -1);
}
setData(data.N(), -1);
}
private void setData(int orderIndex, int currentIndex){
data.orderIndex = orderIndex;
data.currentIndex = currentIndex;
frame.render(data);
AlgorithmHelper.pause(DELAY);
}
都是常规操作。
MergeSort
归并排序本身的思路，面对一个数组想要让他排序，首先把数组分成两部分，用同样的算法把两边排序，最后归并两边。在划分的时候，划分到不能再划分为止。首先同样要有一个归并的数据类：
public class MergeData {
private int[] numbers;
public int l, r;
public int mergeIndex;
public MergeData(int N, int randomBound) {
numbers = new int[N];
for (int i = 0; i < N; i++) {
numbers[i] = (int) (Math.random() * randomBound) + 1;
//System.out.println(numbers[i]);
}
}
public int N(){
return numbers.length;
}
public int get(int index){
if (index < 0 || index >= numbers.length){
throw new IllegalArgumentException("index is illgel!");
}
return numbers[index];
}
public void set(int index, int num){
if (index < 0 || index >= numbers.length){
throw new IllegalArgumentException("index is illgel!");
}
numbers[index] = num;
}
public void swap(int i, int j){
int t = numbers[i];
numbers[i] = numbers[j];
numbers[j] = t;
}
}
用l和r来表示正在归并的数组范围，mergeIndex表示已经进行归并了的集合。归并整个过程前面的博客有写，不再复述了。
private void run() {
setData(-1, -1, -1 );
Merge(0, data.N()-1);
setData(0, data.N()-1, -1);
}
private void Merge(int l, int r) {
if (l >= r) {
return;
}
setData(l, r, -1);
int mid = (l + r) / 2;
Merge(l, mid);
Merge(mid + 1, r);
merge(l, r, mid);
}
private void merge(int l, int r, int mid) {
int[] array = new int[r - l + 1];
for (int i = l; i <= r; i++) {
array[i - l] = data.get(i);
}
int i = l, j = mid + 1;
int index = l;
while (i <= mid && j <= r) {
if (array[i - l] < array[j - l]) {
data.set(index, array[i - l]);
i++;
index++;
} else {
data.set(index, array[j - l]);
j++;
index++;
}
setData(l, r, index);
}
if (i <= mid) {
for (int k = i; k <= mid; k++) {
data.set(index, array[k - l]);
index++;
setData(l, r, index);
}
} else if (j <= r) {
for (int k = j; k <= r; k++) {
data.set(index, array[k - l]);
index++;
setData(l, r, index);
}
}
}
效果：
QuickSort
快速排序，快速排序是在平均情况下比较快的算法了。每一次把第一个元素作为标定的位置，把这个位置放到合适的位置即可。首先还是需要一个快拍数据类：
public class QuickSortData {
private int[] numbers;
public int l, r;
public int Index;
public QuickSortData(int N, int randomBound) {
numbers = new int[N];
for (int i = 0; i < N; i++) {
numbers[i] = (int) (Math.random() * randomBound) + 1;
//System.out.println(numbers[i]);
}
}
public int N(){
return numbers.length;
}
public int get(int index){
if (index < 0 || index >= numbers.length){
throw new IllegalArgumentException(index + "index is illgel!");
}
return numbers[index];
}
public void set(int index, int num){
if (index < 0 || index >= numbers.length){
throw new IllegalArgumentException("index is illgel!");
}
numbers[index] = num;
}
public void swap(int i, int j){
int t = numbers[i];
numbers[i] = numbers[j];
numbers[j] = t;
}
}
和前面的归并排序一样，l和r用不同的颜色。
private void run() {
setData(-1, -1, -1);
QuickSort(0, data.N() - 1);
setData(0, data.N() - 1, -1);
}
private void QuickSort(int l, int r) {
if (l >= r) {
return;
}
setData(l, r, -1);
int mid = partition(l, r);
QuickSort(l, mid - 1);
QuickSort(mid + 1, r);
frame.render(data);
AlgorithmHelper.pause(DELAY);
}
private int partition(int l, int r) {
int v = data.get(l);
int i = l + 1;
int j = r;
setData(l, r, l);
while (true) {
while (i <= r && data.get(i) < v) {
i++;
}
while (j >= l + 1 && data.get(j) > v) {
j--;
}
if (i > j) {
break;
}
data.swap(i, j);
setData(l, r, l);
i++;
j--;
}
data.swap(j, l);
setData(l, r, j);
return j;
}
和前面基本一致。
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