洛谷P5733、P5734、P5735、P5739题题解（Java语言描述）

P5733题目要求

P5733题目链接

P5733分析

toUpperCase()就行了……

P5733AC代码（Java语言描述）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        String str2 = str.toUpperCase();
        System.out.println(str2);
        scanner.close();
    }
}

P5734题目要求

P5734题目链接

P5734分析

为每个命令编写自己的函数，按要求实现即可……

P5734AC代码（Java语言描述）

import java.util.Scanner;

public class Main {

    private static String doc = "";

    private static void append(String append_doc) {
        doc = doc + append_doc;
    }

    private static void cut(int from, int range) {
        doc = doc.substring(from, from+range);
    }

    private static void insert(int from, String insert_doc) {
        String head = doc.substring(0, from);
        String rear = doc.substring(from);
        doc = head + insert_doc + rear;
    }

    private static int search(String search_key) {
        return doc.indexOf(search_key);
    }

    private static String getResult(String command) {
        String[] arr = command.split(" ");
        if (command.startsWith("1")) {
            append(arr[1]);
            return doc;
        } else if (command.startsWith("2")) {
            cut(Integer.parseInt(arr[1]), Integer.parseInt(arr[2]));
            return doc;
        } else if (command.startsWith("3")) {
            insert(Integer.parseInt(arr[1]), arr[2]);
            return doc;
        } else {
            return Integer.toString(search(arr[1]));
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = Integer.parseInt(scanner.nextLine());
        doc = scanner.nextLine();
        String[] result = new String[num];
        for (int i = 0; i < num; i++) {
            result[i] = getResult(scanner.nextLine());
        }
        scanner.close();
        for (String s : result) {
            System.out.println(s);
        }
    }

}

P5735题目要求

P5735题目链接

P5735分析

C = a + b + c 嘛，每条边长就作差平方开根，大家都懂的OK……

P5735AC代码（Java语言描述）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double x1 = scanner.nextDouble(), y1 = scanner.nextDouble(), x2 = scanner.nextDouble(),
                y2 = scanner.nextDouble(), x3 = scanner.nextDouble(), y3 = scanner.nextDouble();
        double l1 = Math.sqrt(Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2));
        double l2 = Math.sqrt(Math.pow(x3-x2, 2) + Math.pow(y3-y2, 2));
        double l3 = Math.sqrt(Math.pow(x3-x1, 2) + Math.pow(y3-y1, 2));
        System.out.printf("%.2f", l1+l2+l3);
        scanner.close();
    }
}

P5739题目要求

P5739题目链接

P5739分析

不循环，那就是递归，写个递归的阶乘很水的啦……

P5739AC代码（Java语言描述）

import java.math.BigInteger;
import java.util.Scanner;

public class Main {

    private static BigInteger calculate_factorial(BigInteger num, BigInteger result) {
        if (num.equals(new BigInteger("0"))) {
            return new BigInteger("1");
        } else if (num.equals(new BigInteger("1"))) {
            return result;
        } else {
            result = result.multiply(num);
            return calculate_factorial(num.subtract(new BigInteger("1")), result);
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        BigInteger limit = new BigInteger(scanner.next());
        scanner.close();
        System.out.println(calculate_factorial(limit, new BigInteger("1")));
    }

}