/*perform T independent experiments on an N-by-N grid*/
public PercolationStats(int N, int T) {
if (N > 0 && T > 0) {
simResTab = new double[T];
repeatCnt = T;
int elemCnt = N * N;
for (int i = 0; i < T; i++) {
Percolation perc = new Percolation(N);
int cntr = 0;
int row, col;
do {
do {
row = StdRandom.uniform(1, N + 1);
col = StdRandom.uniform(1, N + 1);
} while (perc.isOpen(row, col));
perc.open(row, col);
cntr++;
} while (!perc.percolates());
simResTab[i] = (double) cntr / elemCnt;
perc = null;
}
} else {
throw new java.lang.IllegalArgumentException();
}
}
public PercolationStats(int N, int T) { // perform T independent experiments on an N-by-N grid
if (N <= 0) {
throw new IllegalArgumentException("The grid size must be bigger than zero");
}
if (T <= 0) {
throw new IllegalArgumentException("The number of experiments must be bigger than zero");
}
double[] percolationThresholds = new double[T];
for (int i = 0; i < T; i++) {
Percolation percolation = new Percolation(N);
int runs = 0;
while (!percolation.percolates()) {
int column;
int row;
do {
column = 1 + StdRandom.uniform(N);
row = 1 + StdRandom.uniform(N);
} while (percolation.isOpen(row, column));
percolation.open(row, column);
runs++;
}
percolationThresholds[i] = runs / (double) (N * N);
}
mean = StdStats.mean(percolationThresholds);
stddev = StdStats.stddev(percolationThresholds);
double confidenceFraction = (1.96 * stddev()) / Math.sqrt(T);
confidenceLo = mean - confidenceFraction;
confidenceHi = mean + confidenceFraction;
}
// perform T independent experiments on an N-by-N grid
public PercolationStats(int N, int T) {
if (N <= 0 || T <= 0)
throw new IllegalArgumentException("Neither 'N' or 'T' cannot be equals or less than zero.");
n = N;
t = T;
Percolation p;
thresholds = new double[T];
int i, j, x;
for (int z = 0; z < T; z++) {
x = 0;
p = new Percolation(n);
while (!p.percolates()) {
i = StdRandom.uniform(1, n + 1);
j = StdRandom.uniform(1, n + 1);
if (!p.isOpen(i, j)) {
p.open(i, j);
x++;
}
}
thresholds[z] = x / (double) (n * n);
/*StdOut.println("Threshold " + String.valueOf(z + 1) + ": " +
thresholds[z]);*/
}
}
/** Perform T independent experiments on an N sized percolation systme. */
public PercolationStats(int N, int T) {
if ((N <= 0) || (T <= 0)) {
throw new IllegalArgumentException();
}
percolationThresholds = new double[T];
for (int i = 0; i < T; i++) {
Percolation p = new Percolation(N);
int numOpenSites = 0;
// Open sites at random until the system percolates.
while (!p.percolates()) {
int x = StdRandom.uniform(1, N + 1);
int y = StdRandom.uniform(1, N + 1);
if (!p.isOpen(x, y)) {
p.open(x, y);
numOpenSites++;
}
}
percolationThresholds[i] = (double) numOpenSites / (N * N);
}
}
public static void main(String[] args) // test client (optional)
{
final int num_tests = 1000;
final int grid_size = 20;
StdOut.println("Begin Generating Random Sites...");
int row, col, count;
double sum = 0.0;
for (int i = 0; i < num_tests; i++) {
count = 0;
Percolation p = new Percolation(grid_size);
while (!p.percolates()) {
// choose site at random
row = StdRandom.uniform(1, grid_size + 1);
col = StdRandom.uniform(1, grid_size + 1);
if (!p.isOpen(row, col)) {
p.open(row, col);
count++;
}
}
sum += count;
}
StdOut.println("Average number of sites opened: " + sum / num_tests);
}
public PercolationStats(int N, int T) {
// perform T independent experiments on an N-by-N grid
if (N <= 0 || T <= 0) {
throw new IllegalArgumentException("N & T should be > 0");
}
arrayMean = new double[T];
testNum = T;
while (T-- > 0) {
openCount = 0;
Percolation gridObj = new Percolation(N);
while (!gridObj.percolates()) {
firstRand = StdRandom.uniform(N + 1);
while (firstRand == 0) firstRand = StdRandom.uniform(N + 1);
secondRand = StdRandom.uniform(N + 1);
while (secondRand == 0) secondRand = StdRandom.uniform(N + 1);
// System.out.print(firstRand+" "+secondRand + "\n");
if (!gridObj.isOpen(firstRand, secondRand)) {
gridObj.open(firstRand, secondRand);
openCount++;
}
}
arrayMean[index++] = openCount / (double) (N * N);
}
}
// perform T independent experiments on an N-by-N grid
public PercolationStats(int N, int T) {
if (N <= 0 || T <= 0) {
throw new IllegalArgumentException("Given number is not positive");
}
threshold = new double[T];
time = T; // for we have to use times later on
// for each experiment--create a new Percolation object and do open sites until we get
// percolates
for (int i = 0; i < T; i++) {
int count = 0; // used to count the number of opened sites
Percolation p = new Percolation(N);
while (!p.percolates()) {
int row = StdRandom.uniform(N) + 1;
int cln = StdRandom.uniform(N) + 1;
if (!p.isOpen(row, cln)) {
p.open(row, cln);
count++;
}
}
// calculate the threshold ratio after finished
threshold[i] = (double) count / (N * N);
}
}
public static double TrialQuickUnionUF(int N) {
Stopwatch watch = new Stopwatch();
QuickUnionUF uf = new QuickUnionUF(N);
for (int i = 0; i < N; i++) {
int p = StdRandom.uniform(N);
int q = StdRandom.uniform(N);
if (!uf.connected(p, q)) {
uf.union(p, q);
}
}
double time = watch.elapsedTime();
// printTree(uf);
return time;
}
/** return (but do not remove) a random item */
public Item sample() {
if (isEmpty()) {
throw new java.util.NoSuchElementException();
}
int index = StdRandom.uniform(this.size);
return this.a[index];
}
public Item sample() {
// return (but do not remove) a random item
if (isEmpty()) {
throw new NoSuchElementException();
}
int randomnumber = StdRandom.uniform(size);
return arr[randomnumber];
}
// Test Client
public static void main(String[] args) {
int N = StdIn.readInt();
Double[] input = new Double[N];
for (int i = 0; i < N; i++) {
input[i] = StdRandom.uniform();
}
QuickSort.sort3Way(input);
display(input);
}
public static void main(String[] args) {
int n = 10;
StdDraw.setCanvasSize(160, 640);
StdDraw.setXscale(-1, n + 1);
StdDraw.setPenRadius(0.006);
double[] a = new double[n];
for (int i = 0; i < n; i++) a[i] = StdRandom.uniform(0.0, 1.0);
sort(a);
}
public PercolationStats(int n, int t) {
if (n < 1 || t < 1) throw new IndexOutOfBoundsException("Illegal parameter value.");
int row, col;
experimentsCount = t;
count = new double[experimentsCount];
for (int i = 0; i < experimentsCount; i++) {
perc = new Percolation(n);
while (!perc.percolates()) {
row = StdRandom.uniform(n) + 1;
col = StdRandom.uniform(n) + 1;
if (!perc.isOpen(row, col)) {
perc.open(row, col);
count[i]++;
}
}
count[i] = count[i] / (n * n);
}
}
public PercolationStats(int N, int T) {
if (N <= 0 || T <= 0) throw new java.lang.IllegalArgumentException();
double[] results = new double[T];
for (int i = 0; i < T; i++) {
Percolation percolation = new Percolation(N);
int count = 0;
while (!percolation.percolates()) {
int p = StdRandom.uniform(N) + 1;
int q = StdRandom.uniform(N) + 1;
if (!percolation.isOpen(p, q)) {
count++;
percolation.open(p, q);
}
}
results[i] = (double) count / (N * N);
}
mean = StdStats.mean(results);
stdDev = StdStats.stddev(results);
sampleSize = T;
}
private void shuffle() {
Item temp;
int randi;
for (int i = 0; i < N; i++) {
randi = StdRandom.uniform(N);
temp = a[i];
a[i] = a[randi];
a[randi] = temp;
}
}
/** Initializes a random 4-by-4 board, by rolling the Hasbro dice. */
public BoggleBoard() {
M = 4;
N = 4;
StdRandom.shuffle(BOGGLE_1992);
board = new char[M][N];
for (int i = 0; i < M; i++) {
for (int j = 0; j < N; j++) {
String letters = BOGGLE_1992[N * i + j];
int r = StdRandom.uniform(letters.length());
board[i][j] = letters.charAt(r);
}
}
}
/**
* Remove and return a random item
* @return the removed item
*/
public Item dequeue() {
if (isEmpty())
throw new NoSuchElementException("Queue underflow");
int index = StdRandom.uniform(size);
Item item = a[index];
a[index] = a[size - 1];
a[size - 1] = null;
size--;
// shrink size of array if neccessary
if (size > 0 && size == a.length/4) resize(a.length / 2);
return item;
}
public Item dequeue() {
if (size == 0) throw new java.util.NoSuchElementException();
// StdRandom.shuffle(arr, 0, size- 1);
int randomN = StdRandom.uniform(size);
assert (size > 0);
Item item = arr[randomN];
swap(randomN, size - 1);
arr[size - 1] = null;
size--;
if (size > 0 && size == arr.length / 4) {
resize((arr.length) / 2);
}
return item;
}
/** remove and return a random item */
public Item dequeue() {
if (isEmpty()) {
throw new java.util.NoSuchElementException();
}
int index = StdRandom.uniform(this.size);
this.size--;
exchange(index, this.size);
Item item = this.a[this.size];
this.a[this.size] = null;
if (this.size > 0 && this.size == this.a.length / 4) {
resize(this.a.length / 2);
}
return item;
}
/**
* Remove and return a random item
*
* @return the random item
*/
public Item dequeue() {
if (N == 0) throw new java.util.NoSuchElementException();
int i = StdRandom.uniform(N);
exch(i, N - 1);
Item item = a[N - 1];
a[N - 1] = null; // don't loiter
N--;
if (N > 0 && N == a.length / 4) resize(a.length / 2);
return item;
}
/**
* Item dequeue() 删除并随机返回一个元素(取样且不放回) 删除一个元素时，随机交换某个元素(索引在0和N-1之间)和末位元素(索引为N-1)的位置，然后像
* ResizingArrayStack 一样删除并返回末位元素。
*
* @return
*/
public Item dequeue() {
if (isEmpty()) {
return null;
} else {
int randi = StdRandom.uniform(N); // 0 - N
Item item = a[randi];
a[randi] = a[N - 1]; // exchange randi last
a[N - 1] = null; // 防止对象游离
N--;
if (N == a.length / 4) {
resize(a.length / 2);
}
return item;
}
}
public PercolationStats(int N, int T) { // perform T independent experiments on an N-by-N grid
if (N <= 0 || T <= 0) throw new IllegalArgumentException();
t = T;
a = new double[T];
for (int i = 0; i < T; i++) {
Percolation percolation = new Percolation(N);
int cnt = 0;
while (!percolation.percolates()) {
int x, y;
do {
int rand = StdRandom.uniform(N * N);
x = rand / N + 1;
y = rand % N + 1;
} while (percolation.isOpen(x, y));
cnt += 1;
percolation.open(x, y);
}
a[i] = 1.0 * cnt / (N * N);
}
}
public static void main(String[] args) {
int numOutputs = Integer.parseInt(args[0]);
RandomizedQueue<String> rq = new RandomizedQueue<String>();
String[] tokens = StdIn.readAllStrings();
int numTokens = tokens.length;
for (int i = 0; i < numOutputs; i++) {
int r = StdRandom.uniform(numTokens);
rq.enqueue(tokens[r]);
tokens[r] = tokens[numTokens - 1];
tokens[numTokens - 1] = null;
numTokens--;
}
for (int i = 0; i < numOutputs; i++) {
System.out.println(rq.dequeue());
}
}
/**
* Return (but do not remove) a random item
*
* @return the item
*/
public Item sample() {
if (N == 0) throw new java.util.NoSuchElementException();
int i = StdRandom.uniform(N);
return a[i];
}
/**
* return (but do not remove) a random item
* @return the an random item
*/
public Item sample() {
if (isEmpty())
throw new NoSuchElementException("Queue underflow");
Item item = a[StdRandom.uniform(size)];
return item;
}
/**
* Item sample() 随机返回一个元素但不删除它(取样且放回)
*
* @return
*/
public Item sample() {
int randi = StdRandom.uniform(N);
return a[randi];
}