[编程题]字符串加解密
- 热度指数：276153 时间限制：C/C++ 1秒，其他语言2秒 空间限制：C/C++ 32M，其他语言64M
- 算法知识视频讲解
输入描述:
第一行输入一个长度为
的字符串
，代表给定的明文字符串；
的字符串
，代表给定的密文字符串。
输出描述:
示例1
输入
abcdefg1 0BCDEFGH
输出
BCDEFGH2 9abcdefg
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
String line = sc.nextLine();
String line1 = sc.nextLine();
char[] chars = line.toCharArray();
char[] chars1 = line1.toCharArray();
System.out.println(encipher(chars));
System.out.println(decrypt(chars1));
}
}
// 加密
private static StringBuilder encipher(char[] chars) {
StringBuilder builder = new StringBuilder();
for (int i = 0; i < chars.length; i++) {
if (Character.isLetter(chars[i])) {
if (Character.isUpperCase(chars[i])) {
// 转小写
char toLowerCase = Character.toLowerCase(chars[i]);
builder.append(Character.isLetter((char)(toLowerCase + 1))?(char)(toLowerCase + 1):"a");
} else {
// 转大写
char toUpperCase = Character.toUpperCase(chars[i]);
builder.append(Character.isLetter((char)(toUpperCase + 1))?(char)(toUpperCase + 1):"A");
}
} else {
Integer integer = Integer.valueOf(chars[i])-48;
builder.append((integer + 1) % 10);
}
}
return builder;
}
// 解密
private static StringBuilder decrypt(char[] chars) {
StringBuilder builder = new StringBuilder();
for (int i = 0; i < chars.length; i++) {
if (Character.isLetter(chars[i])) {
if (Character.isUpperCase(chars[i])) {
char toLowerCase = Character.toLowerCase(chars[i]);
builder.append(Character.isLetter((char)(toLowerCase - 1))?(char)(toLowerCase - 1):"z");
} else {
char toUpperCase = Character.toUpperCase(chars[i]);
builder.append(Character.isLetter((char)(toUpperCase - 1))?(char)(toUpperCase - 1):"Z");
}
} else {
Integer integer = Integer.valueOf(chars[i])-48;
builder.append((integer - 1) % 10 < 0 ? 9 : (integer - 1) % 10);
}
}
return builder;
}
发表于 2024-12-04 11:27:11
回复(0)
import java.util.Scanner;
import java.lang.Character;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String text = in.next();
String code = in.next();
System.out.println(encode(text));
System.out.println(decode(code));
}
public static String encode(String text) {
String code = "";
for (char c : text.toCharArray()) {
if (Character.isDigit(c)) {
code += (c + 3) / 10 == 5 ? (char)(c + 1) : '0';
} else if (Character.isLowerCase(c)) {
code += (c + 8) / 26 == 4 ? (char)(c - 31) : 'A';
} else if (Character.isUpperCase(c)) {
code += (c + 14) / 26 == 3 ? (char)(c + 33) : 'a';
} else {
code += c;
}
}
return code;
}
public static String decode(String code) {
String text = "";
for (char c : code.toCharArray()) {
if (Character.isDigit(c)) {
text += (c + 2) % 10 > 0 ? (char)(c - 1) : '9';
} else if (Character.isLowerCase(c)) {
text += (c + 7) % 26 > 0 ? (char)(c - 33) : 'Z';
} else if (Character.isUpperCase(c)) {
text += (c + 13) % 26 > 0 ? (char)(c + 31) : 'z';
} else {
text += c;
}
}
return text;
}
}
发表于 2024-09-18 23:50:43
回复(0)
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String str1 = in.nextLine();
String str2 = in.nextLine();
//使用字典法，简洁明了
String a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
String b = "BCDEFGHIJKLMNOPQRSTUVWXYZAbcdefghijklmnopqrstuvwxyza1234567890";
StringBuilder out1 = new StringBuilder();
StringBuilder out2 = new StringBuilder();
for (int i = 0; i < str1.length(); i++) {
out1.append(b.charAt(a.indexOf(str1.charAt(i))));
}
for (int i = 0; i < str2.length(); i++) {
out2.append(a.charAt(b.indexOf(str2.charAt(i))));
}
System.out.println(out1);
System.out.println(out2);
}
}
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String str1 = in.nextLine();
String str2 = in.nextLine();
//使用字典法，简洁明了
String a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
String b = "BCDEFGHIJKLMNOPQRSTUVWXYZAbcdefghijklmnopqrstuvwxyza1234567890";
StringBuilder out1 = new StringBuilder();
StringBuilder out2 = new StringBuilder();
for (int i = 0; i < str1.length(); i++) {
out1.append(b.charAt(a.indexOf(str1.charAt(i))));
}
for (int i = 0; i < str2.length(); i++) {
out2.append(a.charAt(b.indexOf(str2.charAt(i))));
}
System.out.println(out1);
System.out.println(out2);
}
}
编辑于 2024-01-10 19:35:04
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextLine()) { // 注意 while 处理多个 case
String one = in.nextLine();
char[] oneArr = one.toCharArray();
String two = in.nextLine();
char[] twoArr = two.toCharArray();
StringBuffer enc = new StringBuffer();
StringBuffer dec = new StringBuffer();
for (char c : oneArr) {
enc.append(convert(c,1));
}
for (char c : twoArr) {
dec.append(convert(c,2));
}
System.out.println(enc);
System.out.println(dec);
}
}
private static char convert(char a, int type) {
if (type == 1){
if (a >= 'a' && a < 'z') {
return (char) (a - 31);
}
if (a >= 'A' && a < 'Z') {
return (char) (a + 33);
}
if (a >= '0' && a < '9') {
return (char) (a + 1);
}
if (a == 'z') {
return 'A';
}
if (a == 'Z') {
return 'a';
}
if (a == '9') {
return '0';
}
}else {
if (a > 'a' && a <= 'z') {
return (char) (a - 33);
}
if (a > 'A' && a <= 'Z') {
return (char) (a + 31);
}
if (a > '0' && a <= '9') {
return (char) (a - 1);
}
if (a == 'a') {
return 'Z';
}
if (a == 'A') {
return 'z';
}
if (a == '0') {
return '9';
}
}
return a;
}
}
编辑于 2023-12-26 10:25:07
回复(0)
一对一线性关系，且数量较少，直接建表查找。
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
char[] in1 = in.nextLine().toCharArray();
char[] in2 = in.nextLine().toCharArray();
String src = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
String code = "bcdefghijklmnopqrstuvwxyzaBCDEFGHIJKLMNOPQRSTUVWXYZA1234567890";
StringBuilder sb = new StringBuilder();
for (int i = 0; i < in1.length; i++) {
sb.append(code.charAt(src.indexOf(in1[i])));
}
System.out.println(sb);
sb.setLength(0);
for (int i = 0; i < in2.length; i++) {
sb.append(src.charAt(code.indexOf(in2[i])));
}
System.out.println(sb);
}
}
发表于 2023-12-15 21:41:44
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String s1 = in.nextLine();
String s2 = in.nextLine();
StringBuilder encoding = new StringBuilder();
StringBuilder decoding = new StringBuilder();
for(int i = 0; i < s1.length(); i++){
char c = s1.charAt(i);
if( c >= 'a' && c <= 'z'){
encoding.append((char)('A'+(c - 'a' + 1) % 26));
}else if ( c >= 'A' && c <= 'Z'){
encoding.append((char)('a'+(c - 'A' + 1) % 26));
}else{
encoding.append((char)('0'+(c - '0' + 1) % 10));
}
}
for(int i = 0; i < s2.length(); i++){
char c = s2.charAt(i);
if( c >= 'a' && c <= 'z'){
decoding.append((char)('Z'+(c - 'z' - 1) % 26));
}else if ( c >= 'A' && c <= 'Z'){
decoding.append((char)('z'+(c - 'Z' - 1) % 26));
}else{
decoding.append((char)('9'+(c - '9' - 1) % 10));
}
}
System.out.println(new String(encoding));
System.out.print(new String(decoding));
}
}
发表于 2023-11-22 23:03:41
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
char[] zip = in.nextLine().toCharArray();
char[] unzip = in.nextLine().toCharArray();
for (int i = 0; i < zip.length; i ++) {
zip[i] = change(zip[i], 1);
}
for (int i = 0; i < unzip.length; i ++) {
unzip[i] = change(unzip[i], -1);
}
System.out.println(new String(zip));
System.out.println(new String(unzip));
}
}
public static char change(char c, int k) {
if (Character.isLowerCase(c)) {
int val = (c - 'a' + k + 26) % 26;
return (char)('A' + val);
} else if (Character.isUpperCase(c)) {
int val = (c - 'A' + k + 26) % 26;
return (char)('a' + val);
} else {
int val = (c - '0' + k + 10) % 10;
return (char)('0' + val);
}
}
}
发表于 2023-10-16 23:47:11
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String arr[]=new String [2];
int index=0;
while(in.hasNextLine()){
arr[index]=in.nextLine();
index++;
}
for(int i=0;i<arr[0].length();i++){
if(i<arr[0].length()-1){
if(arr[0].charAt(i)>='A'&&arr[0].charAt(i)<'Z'){
int num=((int)arr[0].charAt(i))+33;
System.out.print((char)num);
}else if(arr[0].charAt(i)=='Z'){
System.out.print("a");
}else if(arr[0].charAt(i)>='a'&&arr[0].charAt(i)<'z'){
int num=((int)arr[0].charAt(i))-31;
System.out.print((char)num);
}else if(arr[0].charAt(i)=='z') {
System.out.print("A");
}else if(arr[0].charAt(i)>='0'&&arr[0].charAt(i)<'9'){
int num=((int)arr[0].charAt(i))+1;
System.out.print((char)num);
}else if(arr[0].charAt(i)=='9') {
System.out.print("0");
}
}else {
if(arr[0].charAt(i)>='A'&&arr[0].charAt(i)<'Z'){
int num=((int)arr[0].charAt(i))+33;
System.out.println((char)num);
}else if(arr[0].charAt(i)=='Z'){
System.out.println("a");
}else if(arr[0].charAt(i)>='a'&&arr[0].charAt(i)<'z'){
int num=((int)arr[0].charAt(i))-31;
System.out.println((char)num);
}else if(arr[0].charAt(i)=='z') {
System.out.println("A");
}else if(arr[0].charAt(i)>='0'&&arr[0].charAt(i)<'9'){
int num=((int)arr[0].charAt(i))+1;
System.out.println((char)num);
}else if(arr[0].charAt(i)=='9') {
System.out.println("0");
}
}
}
for(int i=0;i<arr[1].length();i++) {
if (arr[1].charAt(i) > 'A' && arr[1].charAt(i) <= 'Z') {
int num = ((int) arr[1].charAt(i)) + 31;
System.out.print((char) num);
} else if (arr[1].charAt(i) == 'A') {
System.out.print("z");
} else if (arr[1].charAt(i) > 'a' && arr[1].charAt(i) <= 'z') {
int num = ((int) arr[1].charAt(i))-33;
System.out.print((char) num);
} else if (arr[1].charAt(i) == 'a') {
System.out.print("Z");
} else if (arr[1].charAt(i) > '0' && arr[1].charAt(i) <= '9') {
int num = ((int) arr[1].charAt(i)) - 1;
System.out.print((char) num);
} else if (arr[1].charAt(i) == '0') {
System.out.print("9");
}
}
}
}
发表于 2023-09-16 12:21:12
回复(0)
应该是最简单明了的Java代码了：
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String encode = sc.next();
String decode = sc.next();
encode(encode);
decode(decode);
}
public static void encode(String encode) {
char[] chars = encode.toCharArray();
for (int i = 0; i < chars.length; i++) {
if (Character.isUpperCase(chars[i])) {
chars[i] = chars[i] == 'Z' ? 'a' : (char) (chars[i] + 1 + 32);
} else if (Character.isLowerCase(chars[i])) {
chars[i] = chars[i] == 'z' ? 'A' : (char) (chars[i] + 1 - 32);
} else if (Character.isDigit(chars[i])) {
chars[i] = chars[i] == '9' ? '0' : (char) (chars[i] + 1);
}
}
System.out.println(String.valueOf(chars));
}
public static void decode(String decode) {
char[] chars = decode.toCharArray();
for (int i = 0; i < chars.length; i++) {
if (Character.isUpperCase(chars[i])) {
chars[i] = chars[i] == 'A' ? 'z' : (char) (chars[i] - 1 + 32);
} else if (Character.isLowerCase(chars[i])) {
chars[i] = chars[i] == 'a' ? 'Z' : (char) (chars[i] - 1 - 32);
} else if (Character.isDigit(chars[i])) {
chars[i] = chars[i] == '0' ? '9' : (char) (chars[i] - 1);
}
}
System.out.println(String.valueOf(chars));
}
}
发表于 2023-08-11 20:56:43
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextLine()) { // 注意 while 处理多个 case
String a = in.nextLine();
String b = in.nextLine();
System.out.println(encript(a));
System.out.println(decript(b));
}
}
public static String encript(String str){
char[] data=str.toCharArray();
for(int i=0;i<data.length;i++){
char t=data[i];
if(Character.isLetter(t)){
if(t=='z'){
data[i]='A';
}else if(t=='Z'){
data[i]='a';
}else{
data[i]=(char)((t+1)^' ');
}
}else{
if(t=='9'){
data[i]='0';
}else{
data[i]=(char)(t+1);
}
}
}
return String.valueOf(data);
}
public static String decript(String str){
char[] data=str.toCharArray();
for(int i=0;i<data.length;i++){
char t=data[i];
if(Character.isLetter(t)){
if(t=='a'){
data[i]='Z';
}else if(t=='A'){
data[i]='z';
}else{
data[i]=(char)((t-1)^' ');
}
}else{
if(t=='0'){
data[i]='9';
}else{
data[i]=(char)(t-1);
}
}
}
return String.valueOf(data);
}
}
发表于 2023-08-08 19:25:13
回复(0)
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String str1 = in.nextLine();
String str2 = in.nextLine();
//使用字典法，简洁明了
String a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
String b = "BCDEFGHIJKLMNOPQRSTUVWXYZAbcdefghijklmnopqrstuvwxyza1234567890";
StringBuilder out1 = new StringBuilder();
StringBuilder out2 = new StringBuilder();
for (int i = 0; i < str1.length(); i++) {
out1.append(b.charAt(a.indexOf(str1.charAt(i))));
}
for (int i = 0; i < str2.length(); i++) {
out2.append(a.charAt(b.indexOf(str2.charAt(i))));
}
System.out.println(out1);
System.out.println(out2);
}
}
发表于 2023-08-01 15:53:15
回复(0)
优点是没有使用特殊值 32 进行运算，也不做 a 或者 z 的判断
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String plaintext = in.next();
String ciphertext = in.next();
System.out.println(encrypt(plaintext.toCharArray()));
System.out.println(decrypt(ciphertext.toCharArray()));
}
static char[] encrypt(char[] charArray) {
for (int i = 0; i < charArray.length; i++) {
if (charArray[i] >= 'a' && charArray[i] <= 'z') {
charArray[i] -= 'a';
charArray[i] = (char) ((charArray[i] + 1) % 26);
charArray[i] += 'A';
} else if (charArray[i] >= 'A' && charArray[i] <= 'Z') {
charArray[i] -= 'A';
charArray[i] = (char) ((charArray[i] + 1) % 26);
charArray[i] += 'a';
} else if (charArray[i] >= '0' && charArray[i] <= '9') {
charArray[i] -= '0';
charArray[i] = (char) ((charArray[i] + 1) % 10);
charArray[i] += '0';
}
}
return charArray;
}
static char[] decrypt(char[] charArray) {
for (int i = 0; i < charArray.length; i++) {
if (charArray[i] >= 'a' && charArray[i] <= 'z') {
charArray[i] -= 'a';
charArray[i] = (char) ((charArray[i] + 25) % 26);
charArray[i] += 'A';
} else if (charArray[i] >= 'A' && charArray[i] <= 'Z') {
charArray[i] -= 'A';
charArray[i] = (char) ((charArray[i] + 25) % 26);
charArray[i] += 'a';
} else if (charArray[i] >= '0' && charArray[i] <= '9') {
charArray[i] -= '0';
charArray[i] = (char) ((charArray[i] + 9) % 10);
charArray[i] += '0';
}
}
return charArray;
}
}
发表于 2023-07-20 00:14:53
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
String str1 = in.nextLine();
String str2 = in.nextLine();
String result1 = "";
String result2 = "";
//加密
for (int i = 0; i < str1.length(); i++) {
char tmp = str1.charAt(i);
//字符
if (Character.isLetter(str1.charAt(i))) {
if (tmp == 'z') {
tmp = 'a';
} else if (tmp == 'Z') {
tmp = 'A';
} else {
tmp = (char)(tmp + 1);
}
if (tmp >= 'A' && tmp <= 'Z') {
tmp = (tmp + "").toLowerCase().charAt(0);
}else if (tmp >= 'a' && tmp <= 'z') {
tmp = (tmp + "").toUpperCase().charAt(0);
}
//数字
}else if(Character.isDigit(tmp)){
if(tmp!='9'){
tmp=(char)(tmp+1);
}else{
tmp='0';
}
}
result1 += tmp;
}
//解密
for (int i = 0; i < str2.length(); i++) {
char tmp = str2.charAt(i);
//字符
if (Character.isLetter(str2.charAt(i))) {
if (tmp == 'a') {
tmp = 'z';
} else if (tmp == 'A') {
tmp = 'Z';
} else {
tmp = (char)(tmp -1);
}
if (tmp >= 'A' && tmp <= 'Z') {
tmp = (tmp + "").toLowerCase().charAt(0);
}else if (tmp >= 'a' && tmp <= 'z') {
tmp = (tmp + "").toUpperCase().charAt(0);
}
//数字
}else if(Character.isDigit(tmp)){
if(tmp!='0'){
tmp=(char)(tmp-1);
}else{
tmp='9';
}
}
result2 += tmp;
}
System.out.println(result1);
System.out.print(result2);
}
}
发表于 2023-05-27 11:24:08
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String a = in.nextLine();
String b = in.nextLine();
//加密后的字符
StringBuffer encrypt = encrypt(a);
System.out.println(encrypt);
//解密后的字符
StringBuffer decode = decode(b);
System.out.println(decode);
}
public static StringBuffer encrypt(String a) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < a.length(); i++) {
char c = a.charAt(i);
String lt = String.valueOf(c);
if (lt.matches(".*[a-z]")) {
if (lt.equals("z")) {
buf.append("A");
} else {
char alt = (char)(a.charAt(i) + 1);
buf.append(String.valueOf(alt).toUpperCase());
}
}
if (lt.matches(".*[A-Z]")) {
if (lt.equals("Z")) {
buf.append("a");
} else {
char alt = (char)(a.charAt(i) + 1);
buf.append(String.valueOf(alt).toLowerCase());
}
}
if (lt.matches(".*[0-9]")) {
if (lt.equals("9")) {
buf.append("0");
} else {
int i1 = Integer.valueOf(String.valueOf(c)) + 1;
buf.append(i1);
}
}
}
return buf;
}
public static StringBuffer decode(String a) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < a.length(); i++) {
char c = a.charAt(i);
String lt = String.valueOf(c);
if (lt.matches(".*[a-z]")) {
if (lt.equals("a")) {
buf.append("Z");
} else {
char alt = (char)(a.charAt(i) - 1);
buf.append(String.valueOf(alt).toUpperCase());
}
}
if (lt.matches(".*[A-Z]")) {
if (lt.equals("A")) {
buf.append("z");
} else {
char alt = (char)(a.charAt(i) - 1);
buf.append(String.valueOf(alt).toLowerCase());
}
}
if (lt.matches(".*[0-9]")) {
if (lt.equals("0")) {
buf.append("9");
} else {
int i1 = Integer.valueOf(String.valueOf(c)) - 1;
buf.append(i1);
}
}
}
return buf;
}
}
发表于 2023-05-26 10:17:10
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
String a = in.nextLine();
String b = in.nextLine();
StringBuilder up = new StringBuilder();
StringBuilder low = new StringBuilder();
StringBuilder num = new StringBuilder();
int lengthA = a.length();
int lengthB = b.length();
// 输出加密字符串
for (int i = 0; i < lengthA; i++) {
char c = a.charAt(i);
if (Character.isUpperCase(c)) {
// up.append(Character.toLowerCase(c));
c = (char) (c + 1);
c = c > 'Z' ? 'A' : c;
c = Character.toLowerCase(c);
System.out.printf("" + c);
} else if (Character.isLowerCase(c)) {
// low.append(Character.toUpperCase(c));
c = (char) (c + 1);
c = c > 'z' ? 'a' : c;
c = Character.toUpperCase(c);
System.out.printf("" + c);
} else {
// num.append(c == '9' ? '0' : (c + 1));
c = (char) (c + 1);
if (c > '9') {
c = '0';
}
System.out.printf("" + c);
}
}
System.out.printf("\n");
// 输出解密字符串
for (int i = 0; i < lengthB; i++) {
char c = b.charAt(i);
if (Character.isUpperCase(c)) {
// up.append(Character.toLowerCase(c));
c = (char) (c - 1);
c = c < 'A' ? 'Z' : c;
c = Character.toLowerCase(c);
System.out.printf("" + c);
} else if (Character.isLowerCase(c)) {
// low.append(Character.toUpperCase(c));
c = (char) (c - 1);
c = c < 'a' ? 'z' : c;
c = Character.toUpperCase(c);
System.out.printf("" + c);
} else {
// num.append(c == '9' ? '0' : (c + 1));
c = (char) (c - 1);
if (c < '0') {
c = '9';
}
System.out.printf("" + c);
}
}
System.out.printf("\n");
}
}
}
发表于 2023-05-23 12:59:41
回复(0)
算了，还是这样吧!
简单明了，不需要多思考
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while (scanner.hasNext()) {
System.out.println(encodeString(scanner.next()));
System.out.println(decodeString(scanner.next()));
}
}
public static String encodeString(String string) {
char[] chars = string.toCharArray();
StringBuilder builder = new StringBuilder();
for (char aChar : chars) {
char next = (char) (aChar + 1);
if (Character.isLowerCase(aChar)) {
if (aChar == 'z') {
builder.append('A');
continue;
}
builder.append(Character.toUpperCase(next));
}
if (Character.isUpperCase(aChar)) {
if (aChar == 'Z') {
builder.append('a');
continue;
}
builder.append(Character.toLowerCase(next));
}
if (Character.isDigit(aChar)) {
if (aChar == '9') {
builder.append('0');
continue;
}
builder.append(next);
}
}
return builder.toString();
}
public static String decodeString(String string) {
char[] chars = string.toCharArray();
StringBuilder builder = new StringBuilder();
for (char aChar : chars) {
char next = (char) (aChar - 1);
if (Character.isLowerCase(aChar)) {
if (aChar == 'a') {
builder.append('Z');
continue;
}
builder.append(Character.toUpperCase(next));
}
if (Character.isUpperCase(aChar)) {
if (aChar == 'A') {
builder.append('z');
continue;
}
builder.append(Character.toLowerCase(next));
}
if (Character.isDigit(aChar)) {
if (aChar == '0') {
builder.append('9');
continue;
}
builder.append(next);
}
}
return builder.toString();
}
}
发表于 2023-05-23 08:03:37
回复(0)
半夜打完游戏睡不着就来做一做
看了很多结论都是分开写加解密方法，想了一想不用分别写加解密算法了，直接用相关标识通过数学公式即可用一个方法同时解决加解密
核心公式：
英文字母：strChar[i] = (char) (strChar[i] + charShift * ('A' - 'a') + shift * 1)//charShift：大小写标识；shift：加解密标识；
数字：模运算：（原数 + 偏移 + 模）% 模；
代码如下（Java）
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String enCode = in.nextLine();
String deCode = in.nextLine();
System.out.println(code(true, enCode));
System.out.println(code(false, deCode));
}
public static String code (boolean isCode, String str) {
char[] strChar = str.toCharArray();
int shift = -1;
if (isCode) {
shift = 1;
}
for (int i = 0; i < strChar.length; i ++) {
if (Character.isLetter(strChar[i])) {
int charShift = 1;
if (Character.isUpperCase(strChar[i])) {
charShift = -1;
}
if ((strChar[i] == 'Z' || strChar[i] == 'z') && shift == 1) {
strChar[i] = charShift == -1 ? 'a' : 'A';
} else if ((strChar[i] == 'A' || strChar[i] == 'a') && shift == -1) {
strChar[i] = charShift == -1 ? 'z' : 'Z';
} else {
strChar[i] = (char) (strChar[i] + charShift * ('A' - 'a') + shift * 1);
}
} else {
strChar[i] = (char) ((strChar[i] + shift + 10 - '0') % 10 + '0');
}
}
return new String(strChar);
}
}
发表于 2023-05-15 03:20:49
回复(0)
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