写一个398行,399列的矩阵
#include<iostream>
using namespace std;
int main()
{
float arr1[450];
float c=1.0;
float b=2.0;
int i=0,j=0;
FILE *fp;
for(i=0;i<400;i++)
{
arr1[i]=i;
}
fp=fopen("aaa.txt","w");
for(i=0;i<399;i++)
{
for(j=0;j<=399;j++)
{
if(j==i)
fprintf(fp,"%f%c",b,' ');
else if(j==i+1 && i!=398)
fprintf(fp,"%f%c",c,' ');
else if(j==i-1)
fprintf(fp,"%f%c",c,' ');
else if(j==399)
{
fprintf(fp,"%f%c",arr1[i],' ');
}
else
fprintf(fp,"%f%c",0.0,' ');
}
}
fclose(fp);
cout<<arr1[9]<<endl;
return 0;
}