String类

1.String的遍历

2.转换大小写

3.将其他类型的数据转化为字符串

4.提取字符串

第11届第 1场分类计数

import java.util.Scanner;
 
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String str = sc.next();
		char[] temp = str.toCharArray();
//toCharArray()方法将字符串转换为字符数组
		int upper = 0, lower = 0, digit = 0;
		for (int i = 0; i < temp.length; i++) {
			if ('A' <= temp[i] && temp[i] <= 'Z') {
				upper++;
			} else if ('a' <= temp[i] && temp[i] <= 'z') {
				lower++;
			} else if ('0' <= temp[i] && temp[i] <= '9') {
				digit++;
			}
		}
		System.out.println(upper + " " + lower + " " + digit);
	}
}

第11届第1场字符串编号

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		char[] a = { '0', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
				'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		Scanner sc = new Scanner(System.in);
		String data = sc.next();
		char b[] = data.toCharArray();//字符数组
//		for (char c : b) {
//			System.out.print(c+" ");
//		}
		for (int i = 0; i < b.length; i++) {
			String data2 = b[i] + "" + b[i + 1];
			int c = Integer.parseInt(data2);//将整型数据Integer转换为基本数据类型int
			if (c >= 1 && c <= 26) {
				System.out.print(a[c]);
				i++;
			} else {
				data2 = b[i] + "";
				c = Integer.parseInt(data2);
				System.out.print(a[c]);
			}
		}
	}
}

5.查找

第11届第2场单词分析

import java.util.Scanner;
 
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		int max = 0;
		int index = 0;
		String a = "abcdefghijklmnopqrstuvwxyz";
		int b[] = new int[26];
		for(int i = 0;i<s.length();i++){
			b[a.indexOf(s.charAt(i))]++;			
		}
		for(int j = 0;j<b.length;j++){
			if(b[j]>max){
				max = b[j];
				index = j;
			}
		}
		System.out.println(a.substring(index,index+1));
		System.out.println(max);
	}
}

第11届第2场字串分值和

import java.util.Scanner;
 
public class Main{
    public static void main(String[] args) {
      Scanner scanner = new Scanner(System.in);
      String s=scanner.nextLine();
      int [] pre = new int[27];
      long ans=0;
      int len=s.length();
        for (int i = 1; i <= s.length(); i++) {
            char x=s.charAt(i-1);
            ans+=(i-pre[x-'a'])*(len-i+1);
            pre[x-'a']=i;
        }
        System.out.println(ans);
    }
}

第10届人物相关性分析

第8届最大公共子串

第5届扑克排序