Java 实验一些题
Lab2_3
【问题描述】
在屏幕上显示如下杨辉三角形：
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1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
【输入形式】
从键盘输入整数n（n>=0且n<=12）
【输出形式】
在屏幕上输出n+1行杨辉三角形。
【输入样例】
3
【输出样例】
------1
----11
–121
1331
其中－和*都是空格位
普通解法
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| public class lab2_3 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int lines = scanner.nextInt() + 1;
int[][] arr = new int[lines][];
for (int i = 0; i < arr.length; i++) {
arr[i] = new int[i + 1];
arr[i][0] = 1;
arr[i][i] = 1;
}
for (int i = 2; i < arr.length; i++) {
for (int j = 1; j < i; j++) {
arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];
}
}
for (int i = 0; i < arr.length; i++) {
for (int j = (arr.length - i) * 2; j >= 0; j--) {
System.out.printf(" ");
}
for (int j = 0; j < arr[i].length; j++) {
System.out.printf("%4d", arr[i][j]);
}
System.out.println();
}
}
}
|
队列实现
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| class Myqueue {
public int[] elem;
public int usedSize;
Myqueue() {
this.elem = new int[10];
}
public boolean isFull() {
return this.elem.length == this.usedSize;
}
public void push(int val) {
if (isFull()) {
this.elem = Arrays.copyOf(this.elem, this.elem.length * 2);
} else {
this.elem[this.usedSize] = val;
usedSize++;
}
}
public boolean isEmpty() {
return this.usedSize == 0;
}
public int pop() {
if (isEmpty()) {
return -1;
} else {
int res = this.elem[0];
for (int i = 0; i < elem.length - 1; i++) {
elem[i] = elem[i + 1];
}
usedSize--;
return res;
}
}
}
public class lab2_3_P {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int lines = scanner.nextInt() + 1;
Myqueue myqueue = new Myqueue();
for (int i = 0; i < lines; i++) {
if (i == 0) {
myqueue.push(0);
myqueue.push(1);
} else if (i > 0) {
for (int j = 0; j < i + 2; j++) {
if (j == 0) {
myqueue.push(0);
continue;
}
int e = myqueue.elem[0] + myqueue.elem[1];
myqueue.push(e);
int out = myqueue.pop();
if(out != 0){
System.out.printf("%d ", out);}
}
System.out.println();
}
}
}
}
|
lab7-1
现有如下格式的成绩单(文本格式)score.txt。
name:zhangsan,shuxue 72,wuli 67,yingyu 70
name:lisi,shuxue 92,wuli 98,yingyu 88
name:wangwu,shuxue 68,wuli 80,yingyu 77
要求按行读取成绩单。并在该行的后面加上该同学的总成绩。然后将该行写入到一个名字为scoreAnalysis.txt的文件中。
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| import java.io.*;
import java.util.*;
class Fenxi {
public static String analyze(String line) {
String[] parts = line.split(",");
double sum = 0;
for (int i = 1; i < parts.length; i++) {
String[] pair = parts[i].split(" ");
sum += Double.parseDouble(pair[1]);
}
return line.trim() + " zongFen:" + sum;
}
}
public class AnalysisResult {
public static void main(String[] args) {
try {
Scanner scanner = new Scanner(new File("score.txt"));
PrintWriter writer = new PrintWriter(new File("scoreAnalysis.txt"));
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
String result = Fenxi.analyze(line);
writer.println(result);
}
scanner.close();
writer.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
|
