使用Python，编程以下问题:字符串加密与解密，输入一字符串，按如下规则加密，将原文中每个字符转换为对应的ascii码后，再将该ascii码加上一 100 100至 200 200之间的整数得到的数值即为该字符对应的密文；解密即为上述过程的逆运算。将该字符串加密后再解密，并且显示原文、密文、解密后文本。

加密程序：

import random

def encrypt(string):
    encrypted = ""
    for char in string:
        ascii_val = ord(char)
        shift = random.randint(100, 200)
        encrypted_char = ascii_val + shift
        encrypted += str(encrypted_char) + " "
    return encrypted[:-1]

string = input("请输入要加密的字符串：")
encrypted_string = encrypt(string)
print("加密后的字符串为：", encrypted_string)

解密程序：

def decrypt(encrypted_string):
    decrypted = ""
    encrypted_list = encrypted_string.split(" ")
    for char in encrypted_list:
        ascii_val = int(char)
        shift = ascii_val - 100
        decrypted_char = chr(shift)
        decrypted += decrypted_char
    return decrypted

decrypted_string = decrypt(encrypted_string)
print("解密后的字符串为：", decrypted_string)

完整程序：

import random

def encrypt(string):
    encrypted = ""
    for char in string:
        ascii_val = ord(char)
        shift = random.randint(100, 200)
        encrypted_char = ascii_val + shift
        encrypted += str(encrypted_char) + " "
    return encrypted[:-1]

def decrypt(encrypted_string):
    decrypted = ""
    encrypted_list = encrypted_string.split(" ")
    for char in encrypted_list:
        ascii_val = int(char)
        shift = ascii_val - 100
        decrypted_char = chr(shift)
        decrypted += decrypted_char
    return decrypted

string = input("请输入要加密的字符串：")
encrypted_string = encrypt(string)
print("加密后的字符串为：", encrypted_string)

decrypted_string = decrypt(encrypted_string)
print("解密后的字符串为：", decrypted_string)

示例输入与输出：

输入：

请输入要加密的字符串：hello world

输出：

加密后的字符串为：210 220 206 206 201 224 227 197 220 203 207
解密后的字符串为：hello world