c++标准化输出 setw

#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <io.h>
#include <fstream>
#include<iomanip>
using namespace std;

int main()
{
	ifstream inf;
	inf.open("file.txt", ifstream::in); 	
	string savepath="D:/faceData/";
	string line;
	Mat img;
	int i=0;
	while (!inf.eof())
	{
		getline(inf,line);
		cout<<line<<endl;
		img=imread(line,1);
		stringstream savename;
		savename<<savepath<<setw(2)<<setfill('0')<<i/24<<"_"<<setw(2)<<setfill('0')<<i%24<<".jpg";
		imwrite(savename.str(),img);
		i++;
	}

	return 0;
}

文件重命名