int n;
string s;
char ss[100];
cin >> n;
for (int i=2;i<=n;i++)
{
    for (int j=1;j<=i-1;j++)
    {
        cin >> s;
        memset(ss,'a',sizeof(ss));
        if (s=="x") a[i][j]=999999999;
        else
        {
            for (unsigned int k=0;k<=s.size()-1;k++) ss[k]=s[k];
            a[i][j]=atof(ss);
        }
    }
}
试验成功- -