ofstream file;
        file.open("xinjian.txt");
        file<<canshu1<<endl;
        file<<canshu2<<endl;
        ...
        file.close();

    double A[1000];//开一个足够大的数组
    int cnt = 0;
    FILE *file;
    file= fopen("xinjian.txt", "r");//以只读的方式打开"xinjian.txt"
    if(file== NULL)
        return;
    while(fscanf(file, "%lf", &A[cnt]) != EOF) 
    {
                 cout<<A[cnt]<<endl;
                 cnt++;
                 
    }
    fclose(file);