字符decode处理，特别是%cu,%3等极端情况下的处理

#include <iostream> #include <string> // 尝试对字符串进行URL解码（简单的替换%） std::string try_url_decode(const std::string& encoded_str) { std::string decoded_str = encoded_str; for (size_t pos = 0; pos < decoded_str.length(); ++pos) { if (decoded_str[pos] == '%' && pos + 2 < decoded_str.length()) { // 尝试将"%XX"格式的字符解码 char hex1 = decoded_str[pos + 1]; char hex2 = decoded_str[pos + 2]; if ((hex1 >= '0' && hex1 <= '9') || (hex1 >= 'A' && hex1 <= 'F') || (hex1 >= 'a' && hex1 <= 'f')) { if ((hex2 >= '0' && hex2 <= '9') || (hex2 >= 'A' && hex2 <= 'F') || (hex2 >= 'a' && hex2 <= 'f')) { // 将"%XX"转换为对应的字符 int decoded_char = (16 * (hex1 >= 'A' ? (hex1 & 0x0F) + 9 : hex1 >= 'a' ? (hex1 & 0x0F) + 9 : hex1 - '0')) + (hex2 >= 'A' ? (hex2 & 0x0F) + 9 : hex2 >= 'a' ? (hex2 & 0x0F) + 9 : hex2 - '0'); decoded_str.replace(pos, 3, 1, static_cast<char>(decoded_char)); pos += 2; // 跳过已替换的两个字符 } } } } return decoded_str; } // 判断字符串是否已URL解码 bool is_url_decoded(const std::string& str) { std::string decoded_str = try_url_decode(str); return decoded_str == str; } int main() { std::string encoded_str = "我是嘴巴最甜的瓜瓜"; std::string decoded_str = "%cu12"; std::cout << "Encoded string: " << encoded_str << std::endl; std::cout << "Decoded string: " << decoded_str << std::endl; if (is_url_decoded(encoded_str)) { std::cout << "The encoded string is already URL decoded." << std::endl; } else { std::cout << "The encoded string is not URL decoded." << std::endl; } if (is_url_decoded(decoded_str)) { std::cout << "The decoded string is already URL decoded." << std::endl; } else { std::cout << "The decoded string is not URL decoded." << std::endl; } return 0; }