程序代码：

124
235
152
178
156
142
178
163
159

程序代码：

124|5623
452|6698
178|9995
235|7542
159|8852
152|9963
156|8512
885|9956
754|6523

程序代码：

124|5623
235|7542
152|9963
178|9995
156|8512
142|
178|9995
163|
159|8852

程序代码：

1. 理想输出文档结果，以文档1的内容为模板；若文档2有相同数据，印出其数据；若不，保留空白；
2.理想格式：
程序名称 文档1名称 文档2名称 理想输出文档结果

awk -F"|" ' NR == FNR { arr[$1]=$2; next } {  print $1"|"arr[$1] } '  文档2名称 文档1名称 > 理想输出文档结果

程序代码：

#include <map>
#include <string>
#include <fstream>

using namespace std;

int main()
{
    map<string, string> outMap;
    ifstream fin1("doc1.txt");
    ifstream fin2("doc2.txt");
    ofstream fout("out.txt");
    string key;
    string word;
    string line;
    int delimiterPos;
    map<string, string>::iterator searchRes;

    while (fin1 >> key)
    {
        outMap.insert(make_pair(key, "|"));
    }

    while (fin2 >> line)
    {
        delimiterPos = line.find('|');
        key = line.substr(0, delimiterPos);
        word = line.substr(delimiterPos);
        if ((searchRes = outMap.find(key)) != outMap.end())
            searchRes->second = word;
    }

    for (map<string, string>::iterator iter = outMap.begin(); iter != outMap.end(); ++iter)
    {
        fout << iter->first << iter->second << endl;
    }

    return 0;
}

程序代码：

124|5623
142|
152|9963
156|8512
159|8852
163|
178|9995
235|7542

程序代码：

#include <map>
#include <string>
#include <fstream>
#include <vector>

using namespace std;

int main()
{
    map<string, string> outMap;
    vector<string> keys;
    ifstream fin1("doc1.txt");
    ifstream fin2("doc2.txt");
    ofstream fout("out.txt");
    string key;
    string word;
    string line;
    int delimiterPos;
    map<string, string>::iterator searchRes;

    while (fin1 >> key)
    {
        keys.push_back(key);
        outMap.insert(make_pair(key, "|"));
    }

    while (fin2 >> line)
    {
        delimiterPos = line.find('|');
        key = line.substr(0, delimiterPos);
        word = line.substr(delimiterPos);
        if ((searchRes = outMap.find(key)) != outMap.end())
            searchRes->second = word;
    }

    for (vector<string>::iterator iter = keys.begin(); iter != keys.end(); ++iter)
    {
        searchRes = outMap.find(*iter);
        fout << searchRes->first << searchRes->second << endl;
    }

    return 0;
}