以下程序完成功能：将datatxt文件的所有行加上行号后写到newdatatxt文件中。请将其补充完整。#include fstreamhvoid mainint i=0;char line100;________1__________ ofstream outfile;________2__________ outfileopennewdatatxtiosout; while!infile

#include <fstream.h>

void main() { int i=0; char line[100]; ifstream infile; infile.open("data.txt",ios::in); // (1) 打开读取文件

ofstream outfile;
outfile.open("newdata.txt",ios::out);

while(infile.getline(line,100)) // (3) 读取每一行
{
    i++;
    outfile<<i<<" "<<line<<endl; // (4) 写入行号和内容
}

infile.close();
outfile.close();

}