题解 | #参数解析#

参数解析

https://www.nowcoder.com/practice/668603dc307e4ef4bb07bcd0615ea677

解题思路

题目要求：
- 解析类似xcopy命令的参数
- 参数之间用空格分隔
- 对于带引号的参数，需要作为一个完整参数处理
- 输出参数个数和每个参数值
解题方法：
- 使用状态机处理字符串
- 特别处理引号内的内容
- 按规则分割参数

代码

python
java
cpp

def parse_command(command):
    params = []
    current_param = []
    in_quotes = False
    
    for char in command:
        if char == '"':  # 处理引号
            in_quotes = not in_quotes
        elif char == ' ' and not in_quotes:  # 空格且不在引号内
            if current_param:
                params.append(''.join(current_param))
                current_param = []
        else:  # 普通字符
            current_param.append(char)
    
    # 处理最后一个参数
    if current_param:
        params.append(''.join(current_param))
    
    # 输出结果
    print(len(params))
    for param in params:
        print(param)

while True:
    try:
        command = input().strip()
        parse_command(command)
    except:
        break

import java.util.*;

public class Main {
    public static void parseCommand(String command) {
        List<String> params = new ArrayList<>();
        StringBuilder currentParam = new StringBuilder();
        boolean inQuotes = false;
        
        for (char c : command.toCharArray()) {
            if (c == '"') {  // 处理引号
                inQuotes = !inQuotes;
            } else if (c == ' ' && !inQuotes) {  // 空格且不在引号内
                if (currentParam.length() > 0) {
                    params.add(currentParam.toString());
                    currentParam = new StringBuilder();
                }
            } else {  // 普通字符
                currentParam.append(c);
            }
        }
        
        // 处理最后一个参数
        if (currentParam.length() > 0) {
            params.add(currentParam.toString());
        }
        
        // 输出结果
        System.out.println(params.size());
        for (String param : params) {
            System.out.println(param);
        }
    }
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextLine()) {
            String command = sc.nextLine().trim();
            parseCommand(command);
        }
    }
}

#include <iostream>
#include <string>
#include <vector>
using namespace std;

void parseCommand(string command) {
    vector<string> params;
    string currentParam;
    bool inQuotes = false;
    
    for (char c : command) {
        if (c == '"') {  // 处理引号
            inQuotes = !inQuotes;
        } else if (c == ' ' && !inQuotes) {  // 空格且不在引号内
            if (!currentParam.empty()) {
                params.push_back(currentParam);
                currentParam.clear();
            }
        } else {  // 普通字符
            currentParam += c;
        }
    }
    
    // 处理最后一个参数
    if (!currentParam.empty()) {
        params.push_back(currentParam);
    }
    
    // 输出结果
    cout << params.size() << endl;
    for (const string& param : params) {
        cout << param << endl;
    }
}

int main() {
    string command;
    while (getline(cin, command)) {
        parseCommand(command);
    }
    return 0;
}