两种输出方法的区别？

[zjjh8877227]

程序中注释行为另一种输出（但是无法输出结果）
#include <iostream.h>
#include <stdlib.h>
#include <fstream.h>
#include <time.h>

//#define FILE_OUT "ran.out" void Fill_It(int *ptr_s,int *ptr_u,int *ptr_d,int ran[20])
{
int i,rand_num,temp;
srand(*ptr_s);
for(i=0;i <20;i++)
{
rand_num=rand();
temp=*ptr_d+(rand_num%(*ptr_u-*ptr_d));
ran[i]=temp;
}
}
int main()
{
int seed,ubound,dbound,i,rand1[20],rand2[20];

ofstream SaveFile("rand.txt");
//ofstream output;
//output.open(FILE_OUT,ios::out);
cout <<"please input seed and ubound,dbound:" <<endl;
cin>>seed>>ubound>>dbound;
Fill_It(&seed,&ubound,&dbound,rand1);
for(i=1;i <20;++i)
cout <<rand1[i] <<ends;
cout <<endl;
for(i=1;i<20;++i)
{SaveFile<<rand1[i]<<ends;//output<<rand1[i]<<ends;
}SaveFile<<endl;

cout <<"please input seed and ubound,dbound again:" <<endl;
cin>>seed>>ubound>>dbound;
Fill_It(&seed,&ubound,&dbound,rand2);
for(i=1;i<20;++i)
cout <<rand2[i]<<ends;
cout <<endl;
for(i=1;i<20;++i)
{SaveFile<<rand2[i]<<ends;//output<<rand2[i]<<ends;
}
//output.close();
SaveFile.close();
system("pause");
return 0;
}
这两种输出有什么区别呢？为什么后一种无法输出？

[lily604]

顶

[zjjh8877227]

好神奇，那个地方为什么改成那个（ofstream）,我的那本书说ios，书也有不准的啊

[K行天下]

这样有输出：

#include <iostream.h>
#include <stdlib.h>
#include <fstream.h>
#include <time.h>

#define FILE_OUT "ran.out"
void Fill_It(int *ptr_s,int *ptr_u,int *ptr_d,int ran[20])
{
    int i,rand_num,temp;
    srand(*ptr_s);
    for(i=0;i <20;i++)
      {
          rand_num=rand();
          temp=*ptr_d+(rand_num%(*ptr_u-*ptr_d));
          ran[i]=temp;
      }
}
int main()
{
    int seed,ubound,dbound,i,rand1[20],rand2[20];

//ofstream SaveFile("rand.txt");
ofstream output;
  output.open(FILE_OUT,ofstream::out);//这里改一下！！！！！！！！！！！！！！！！！！！！！！！！！！！
    cout <<"please input seed and ubound,dbound:" <<endl;
    cin>>seed>>ubound>>dbound;
    Fill_It(&seed,&ubound,&dbound,rand1);
    for(i=1;i <20;++i)
      cout <<rand1[i] <<ends;
    cout <<endl;
for(i=1;i <20;++i)
{//SaveFile <<rand1[i] <<ends;
    output <<rand1[i] <<ends;
    }
    //SaveFile <<endl;

cout <<"please input seed and ubound,dbound again:" <<endl;
    cin>>seed>>ubound>>dbound;
Fill_It(&seed,&ubound,&dbound,rand2);
    for(i=1;i <20;++i)
      cout <<rand2[i] <<ends;
    cout <<endl;
for(i=1;i <20;++i)
{//SaveFile <<rand2[i] <<ends;
    output <<rand2[i] <<ends;
    }
output.close();
    //SaveFile.close();
system("pause");
    return 0;
}