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LeetCode

发表于 阅读次数： Valine：
本文字数： 2.3k 阅读时长 ≈ 2 分钟

字符串分割

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/**
     *输入一个字符串，请按长度为8拆分每个输入字符串并进行输出；
     * 长度不是8整数倍的字符串请在后面补数字0，空字符串不处理。
     * 方案：补差达到8的倍数后分组打印
     * @param args
     */
    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        if (str.isEmpty()){
            return;
        }

        StringBuilder wordBuilder = new StringBuilder();
        wordBuilder.append(str);
        int zeroCount = str.length() % 8 == 0 ? 0 : 8 - str.length() % 8;
        for (int i = 1;i <= zeroCount;i++){
            wordBuilder.append(0);
        }
        int groupLength = wordBuilder.length() / 8;
        for (int i = 0;i < groupLength;i++){
            System.out.println(wordBuilder.substring(i * 8,(i + 1) * 8));
        }
    }

进制转换

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import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception{
        Scanner in = new Scanner(System.in);
        while(in.hasNextLine()){
            String s = in.nextLine();
            System.out.println(Integer.parseInt(s.substring(2,s.length()),16));
        }
    }
}

质数因子

、、

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public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()){
            int num = in.nextInt();
            int target = 2;
            do {
                if (num % target == 0){
                    System.out.print(target + " ");
                    num = num / target;
                }else {
                    // 避免循环过多超时
                    if (target > num / target){
                        target = num;
                    }else {
                        target ++ ;
                    }
                }
            }while (num > 1);
        }
    }

取近似值

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import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextFloat()){
            float num = in.nextFloat();
            System.out.println(Math.round(num));

        }
    }
}

字符串排序

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import java.util.*;
// Arrays.sort()排序
public class Main {
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String[] array = new String[n];
        for (int i = 0; i < n; i++) {
            array[i] = in.nextLine();
        }
        Arrays.sort(array);
        for (String str : array) {
            System.out.println(str);
        }
    }
}

求 int 型正整数在内存中存储时 1 的个数

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import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()){
            String str = Integer.toString(in.nextInt(), 2);
            char[] arrays = str.toCharArray();
            int count = 0;
            for (char array : arrays) {
                if ("1".equals(String.valueOf(array))){
                    count ++ ;
                }
            }
            System.out.println(count);
        }
    }
}

购物单【背包问题】