C++统计单词小程序

#include <fstream>
#include <string>
#include <iostream>
#include <map>
using namespace std;

int main()
{
	string str;
	ifstream infile;
	ofstream outfile;
	map<string,int> wordCount;
	map<string,int>::iterator iter;

	infile.open("in.txt");
	outfile.open("out.txt");
	//测试输入文件是否打开
	if (!infile)
	{
		cerr<<"error:unable to open input file:"
			<<infile<<endl;
		return -1;
	}
	while(infile>>str)
	{
		wordCount[str]++;//统计单词出现次数
	}
	for (iter=wordCount.begin();iter!=wordCount.end();++iter)
	{
		cout<<iter->first<<":"<<wordCount[iter->first]<<endl;//标准输出
		outfile<<iter->first<<":"<<wordCount[iter->first]<<endl;//输出到文件
	}
	infile.close();
	outfile.close();
	return 0;
}