297.【华为OD机试】拼接url（字符串处理—Java&Python&C++&JS实现）

题目描述：

给定一组URL组件，请编写代码将这些组件拼接成一个完整的URL。

示例：

输入：
protocol = "http"
host = "leetcode.com"
path = "/path"
query = "query=123"
fragment = "fragment"
输出：
"http://leetcode.com/path?query=123#fragment"

解决方案：

Java 实现：

public class Solution {
    public String buildUrl(String protocol, String host, String path, String query, String fragment) {
        StringBuilder url = new StringBuilder();
        url.append(protocol).append("://").append(host);
        if (path != null) {
            url.append('/').append(path.startsWith("/") ? path.substring(1) : path);
        }
        if (query != null) {
            url.append('?').append(query);
        }
        if (fragment != null) {
            url.append('#').append(fragment);
        }
        return url.toString();
    }
}

Python 实现：

class Solution:
    def buildUrl(self, protocol, host, path, query, fragment):
        url = protocol + "://" + host
        if path:
            url += '/' + path.lstrip('/')
        if query:
            url += '?' + query
        if fragment:
            url += '#' + fragment
        return url

C++ 实现：

#include <iostream>
#include <string>
 
std::string buildUrl(std::string protocol, std::string host, std::string path, std::string query, std::string fragment) {
    std::string url = protocol + "://" + host;
    if (!path.empty()) {
        url += '/' + path.substr(path.starts_with('/') ? 1 : 0);
    }
    if (!query.empty()) {
        url += '?' + query;
    }
    if (!fragment.empty()) {
        url += '#' + fragment;
    }
    return url;
}
 
int main() {
    std::string protocol = "http";
    std::string host = "leetcode.com";
    std::string path = "/path";
    std::string query = "query=123";
    std::string fragment = "fragment";
    std::cout << buildUrl(protocol, host, path, query, fragment) << std::endl;
    return 0;
}

JavaScript 实现：

function buildUrl(protocol, host, path, query, fragment) {
    let url = protocol + "://" + host;
    if (path) {
        url += '/' + path.replace(/^\//, '');
    }
    if (query) {
        url += '?' + query;
    }
    if (fragment) {
        url += '#' + fragment;
    }
    return url;
}
 
// 测试示例
console.log(buildUrl("http", "leetcode.com", "/path", "query=123", "fr