- flipping an image (flip 0 and 1)
Exclusive Or: ^=
vector<vector<int>> flipAndInvertImage(vector<vector<int>>& A) {
for (auto & row : A){
reverse(row.begin(), row.end());
}// reverse()
for (auto & row : A){
for (int & i: row){
i ^= 1;
}
}//exclusive or
return A;
}//flip and invertclass Solution {
public int[][] flipAndInvertImage(int[][] A) {
int C = A[0].length;
for (int[] row: A)
for (int i = 0; i < (C + 1) / 2; ++i) {
int tmp = row[i] ^ 1;
row[i] = row[C - 1 - i] ^ 1;
row[C - 1 - i] = tmp;
}
return A;
}
}用JMol读取.mol或者.xyz，本质上就是写一个txt
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
public class CircleA {
public static void main(String[] args) throws IOException{
float x,y,z = 0;
float radian;
float radius = 10;
int count = 0;
File f = new File("./" + "002" + ".txt"); //./的意思是默认根目录
FileOutputStream fout = new FileOutputStream(f);
PrintStream out = new PrintStream(fout);
out.println("\n" + "Caffine");
for(int theta = 0;theta < 360;theta+=5) {
for (int phi = 0; phi < 360; phi += 5) {
radian = (float) (theta * Math.PI / 180.0);
float phiRadian = (float)(phi * Math.PI /180.0);
x = (float) (radius* Math.sin(phiRadian) * Math.cos(radian)); //球面坐标系
y = (float) (radius* Math.sin(phiRadian) * Math.sin(radian));
z = (float)(radius*Math.cos(phiRadian));
out.println("C " + x + " " + y + " " + z);
count += 1;
System.out.println(count);
}
}
out.close();
}
}在线展示stl：https://www.viewstl.com/
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
public class Folium {
public Folium() {
}
private class Pt {
double x, y, z;
}// Pt
public Folium.Pt calcPt(double u, double v) {
Folium.Pt p = new Folium.Pt(); // we will fill and return this
float uR = (float) (u * Math.PI / 180.0);
float vR = (float) (v * Math.PI / 180);
p.x = (float) (Math.cos(uR) * (2 * vR / Math.PI - Math.tanh(vR)));
p.y = (float) (Math.cos(uR + 2 * Math.PI / 3) / Math.cosh(vR));
p.z = (float) (Math.cos(uR - 2 * Math.PI / 3) / Math.cosh(vR));
return p;
}
public void createSTL() throws IOException {
File f = new File("./" + "F" + ".stl");
FileOutputStream fout = new FileOutputStream(f);
PrintStream out = new PrintStream(fout);
out.println("solid"); // header
for (int u = -180; u < 180; u += 5) {
for (int v = -180; v < 180; v += 5) {
// form an 'upper' tri
out.println("facet normal 0 0 0");
out.println("outer loop");
// verts
Pt v0 = calcPt(u, v);
Pt v1 = calcPt(u, v + 5);
Pt v2 = calcPt(u + 5, v);
out.println("vertex " + v0.x + " " + v0.y + " " + v0.z);
out.println("vertex " + v1.x + " " + v1.y + " " + v1.z);
out.println("vertex " + v2.x + " " + v2.y + " " + v2.z);
out.println("endloop");
out.println("endfacet");
// form a 'lower' tri
out.println("facet normal 0 0 0");
out.println("outer loop");
// verts
v0 = calcPt(u + 5, v);
v1 = calcPt(u, v + 5);
v2 = calcPt(u + 5, v + 5);
out.println("vertex " + v0.x + " " + v0.y + " " + v0.z);
out.println("vertex " + v1.x + " " + v1.y + " " + v1.z);
out.println("vertex " + v2.x + " " + v2.y + " " + v2.z);
out.println("endloop");
out.println("endfacet");
}// next x
}// next y
out.println("endsolid"); // footer
// done!
out.close();
}// createSTL()
public static void main(String[] args) {
Folium f = new Folium();
try {
f.createSTL();
} catch (Exception e) {}
}
}import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.io.IOException;
class TriGrid {
int xRes=10, yRes=10;
/** 改了这里，计算distance */
public float Dist(int i,int j){
float z0;
z0 = (float)Math.sin(Math.sqrt(i*i+j*j));
return z0;
}
public void createFacets(PrintStream out) {
for(int j=0;j<(yRes-1);j++) {
for(int i=0;i<(xRes-1);i++) {
// form an 'upper' tri, between (i,j),(i,j+1),(i+1,j)
out.println("facet normal 0 0 0");
out.println("outer loop");
// verts
out.println("vertex " + i + " " + j + " " + Dist(i,j));
out.println("vertex " + i + " " + (j+1) + " " + Dist(i,j+1));
out.println("vertex " + (i+1) + " " + j + " " + Dist(i+1,j));
out.println("endloop");
out.println("endfacet");
// form a 'lower' tri, between (i+1,j), (i,j+1), (i+1,j+1)).
out.println("facet normal 0 0 0");
out.println("outer loop");
// verts
out.println("vertex " + (i+1) + " " + j + " " + Dist(i+1,j));
out.println("vertex " + i + " " + (j+1) + " " + Dist(i,j+1));
out.println("vertex " + (i+1) + " " + (j+1) + " " + Dist(i+1,j+1));
out.println("endloop");
out.println("endfacet");
}// next x
}// next y
}// createFacets()
public static void main(String[] args) throws IOException {
File f = new File("./grid.stl");
FileOutputStream fout = new FileOutputStream(f);
PrintStream out = new PrintStream(fout);
//now we can println() into out.
out.println("solid"); // header
// the actual facets are written out using a TriGrid object
TriGrid tg = new TriGrid();
tg.createFacets(out);
out.println("endsolid"); // footer
// done!
out.close();
}// main()
}// TriGrid基本和stl之类的文件输出一致，也是改动x,y,z的坐标
import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.io.IOException;
import java.util.Random;
class spheres {
public static void main(String[] args) throws java.io.FileNotFoundException {
int n=100; // try 1000, 10000 as well :)
Random rng = new Random();
// open file
File f = new File("C:\\temp\\test.wrl");
FileOutputStream fout = new FileOutputStream(f);
PrintStream out = new PrintStream(fout);下面进行文件输出的部分，首先写header： ("#VRML 2.0 utf8") 底下用到了一个outputSph的函数，是它后面自己定义了一个，就是格式化输出
out.println("#VRML 2.0 utf8");
// write geometry
for(int i=0;i<n;i++) {
double x = rng.nextFloat();// 0..1
double y = rng.nextFloat();
double z = rng.nextFloat();
//System.out.println(x);
outputSph(x,y,z,out);
}// next
// close file
out.close();
}// main()
public static void outputSph(double x, double y, double z, PrintStream out) {
out.println("# " + x + "," + y + "," + z);
out.println("Transform {");
out.println(" translation " + x + " " + y + " " + z);
out.println(" children [");
outputShape(0.1,out);
out.println(" ]"); // children
out.println("}"); // Transform
}// outputSph()
public static void outputShape(double rad, PrintStream out) {
out.println(" Shape {");
out.println(" appearance Appearance {");
out.println(" material Material {}");
out.println(" }");
out.println(" geometry Sphere {");
out.println(" radius "+rad);
out.println(" }");
out.println(" }#Shape");
}// outputShape()
}// class spheresJFrame frame = new JFrame();//先新建一个JFrame
JPanel p = new JPanel(); //再新建一个JPanel
p.setBackground(Color.WHITE); //这是JPanel的背景色
p.setPreferredSize(new Dimension(xResolution,yResolution)); //这是JPanel画布的大小
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //这里是设置frame关闭的方式，可以当作固定短语复制粘贴
frame.add(p);//把JPanel加到JFrame里
BufferedImage surface = new BufferedImage(xResolution,yResolution,BufferedImage.TYPE_INT_RGB); //新建一个surface
JLabel view = new JLabel(new ImageIcon(surface));//新建一个以surface为参数的JLabel
view.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0)); //无关紧要的话
view.setPreferredSize(new Dimension(xResolution,yResolution));
p.add(view);//把Jlabel view加到JPanel里
Graphics g = surface.createGraphics(); //好了可以画图了！如果是喊你setGraphics()的话，就可以用Graphics自带的drawLine，drawOval之类的函数了 http://bytes.usc.edu/cs455saty/lectures/JavaLang_I/code/CanvasPlot/CanvasPlot.java
/** 注意这个，此处是setGraphics */
Graphics g = surface.setGraphics();
if (drawArc) {
g.setColor(Color.BLUE);
int xx = random.nextInt(60);
int yy = random.nextInt(40);
drawArc(x,y,xx,yy,g);
} else {
drawNode(x,y,g);
}include <fstream>!!!!
使用ofstream + 名字，比如pgmFile，然后输出的时候和Java输出文件是一样的，把所有cout改成pgmFile，也就是你在往pgmFile里写东西
void writeFile(){
ofstream pgmFile("./" + filename +".pgm"); // output image file we're creating //起名为ofstream+名字，比如这里的名字是pgmFile
// 头文件！！！！！注意这里cout替换成了名为pgmFile的ofstream，下面也是一样的
pgmFile << "P2" << endl;
pgmFile << xRes << " " << yRes << endl;
pgmFile << 255 << endl;
// pixel data
for(int i=0;i<yRes;i++){
for(int j=0;j<xRes;j++){
pgmFile << getPixel(j,i) << " ";
}// next column
pgmFile << endl;
}// next row
// 记得把文件关上！！！！！！！
pgmFile.close();
}//writeFile()**就是新建了一个FileOutputStream fout和PrintStream out，然后把所有System.out.println改成out.println!!! **
File f = new File("./" + "F" + ".stl");
FileOutputStream fout = new FileOutputStream(f);
PrintStream out = new PrintStream(fout);
out.println("solid"); // header#include<iostream>
#include<fstream>
using namespace std;
int main()
{
ifstream inFile("C:/temp/feep.pgm");
char a[80];
//这里的意思是如果inFile不存在的话，就略略略
if(!inFile)
{
cerr << "Error opening file.." << endl;
return(1);
}
//这里的意思是如果inFile还没有到头的话，使用
while(!inFile.eof())
{
inFile >> a; // 读取：从文件里读一个单词（token），然后把这个单词存到名为a的变量里
cout << a << endl; // 再把a打印出来
}
inFile.close(); //记得close！！！！！！
return(0);
}// main()import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
public class URLReader {
public static void main(String[] args) throws Exception {
URL myURL = new URL("http://www.usc.edu/");
//注意这句话！！！！！新建了一个BufferedRead的文件
BufferedReader in = new BufferedReader(new InputStreamReader(myURL.openStream()));
String inputLine;
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
in.close();
}
}// URLReaderimport java.io.*;
class readFiles {
public static void main(String args[]) throws Exception {
FileReader fr = new FileReader("WeThePeople.txt");
BufferedReader br = new BufferedReader(fr);
String s;
while((s = br.readLine()) != null) {
System.out.println(s);
}
fr.close();
}
}// readFiles()用java.util.StringTokenizer(splitThis, delim); 或者String object自带的split(delim)。 delim的意思就是分隔符
public class tokenizing {
public static void main(String[] args) {
String delim = ","; // our "delimiter" - what to use, for splitting
String splitThis = "one,two,,three,four,,five"; // our string to split
System.out.println("StringTokenizer:");
java.util.StringTokenizer st = new java.util.StringTokenizer(splitThis, delim);
while (st.hasMoreElements()) {
System.out.println(" "+st.nextElement());
}
System.out.println("\nsplit(): ");
String[] tokens = splitThis.split(delim);
int tokenCount = tokens.length;
for (int j=0; j<tokenCount; j++) {
System.out.println(" "+tokens[j]);
}
}
}// tokenizingpublic class Rnd {
private double last = 0.1; // latest # in our sequence
private double seed = 0.1; // a seed value, between 0.0 and 1.0
private double mpyer = 309.0, adder = 0.203125; // for our LCG formula
private int count = 0; // how many nums served so far
public Rnd(double s) {
seed = s;
last = s;
}// Rnd
public Rnd() {
} //default
public double random() {
last = mpyer * last + adder;
last -= (int) last; // same as last %= 1.0;
count++;
return last;
}// random
public int getCount() {
return count;
}// getCount()
public void reset() {
last = seed;
count = 0;
}// reset
public static void main(String[] args) {
int nThrows = 100000000;
int nInside = 0;
Rnd randomGenerator = new Rnd(0.257);//0.257可以换成别的数字！！！
for (int i = 0; i < nThrows; i++) {
double x = randomGenerator.random();
double y = randomGenerator.random();
if ((x * x + y * y) < 1) {
nInside += 1;
}
}
double pi = 4.0 * nInside / nThrows;
System.out.println(pi);
}//Rnd
}https://blog.csdn.net/RicheyLee/article/details/51066743
class monte{
private double length = 10;
private int total = 10000;
//也可以自己写一个constructor， this.length = xxx, this.total = xxx
public monte(){} //default
public static void main(String[] args) {
Random rng = new Random();
int length = 10;
int nThrows = 100000;
monte area = new monte(length, nThrows);
int nInside = 0;
double lengthSquare = length * length;
for(int i = 0; i <nThrows; i++){
double x = rng.nextDouble() * 10;
double y = rng.nextDouble() * 10;
//pseudo code
if(y<=2-x.^2){
nInside ++;
}else if(y.^3>=x.^2){
nInside ++;
}
}//for
//然后这道题的本质是先求pi
//再求面积
}//main