C++ 二叉树问题，求问哪里出了问题

Question

编了一个欧式期权的二叉树程序，检查感觉没什么错啊，但就是不输出矩阵，求大佬指导

//

#include <cmath>
#include <iostream>
#include<vector>
#include <cstdlib>
#include<stdlib.h>
#include<math.h>
using namespace std;
void inputs(double &r, double &s0, double &k, double &u, double &d, int &T)
{
    cout << "Input interest rate :" << endl;
    cin >> r;
    cout << "Input periods:" << endl;
    cin >> T;
    cout << "Input current stock price:" << endl;
    cin >> s0;
    cout << "Input strike price:" << endl;
    cin >> k;
    cout << "Input u:" << endl;
    cin >> u;
    cout << "Input d:" << endl;
    cin >> d;
}
double multiply(double x, int n)
{
    double a = 1;
    if (n == 0)
    {
        return(a);
    }
    else
    {
        while (a >= 1)
        {
            a = a * x;
            n = n - 1;
        }
        return(a);
    }
}

int main()
{
    double r, s0, k, u, d;
    int T;
    inputs(r, s0, k, u, d, T);
    vector< vector<double> > Matrix(T + 1);
    for (int i = 0; i < T + 1; i++)
    {
        Matrix[i].resize(2 ^ T);
    }
    for (int i = 0; i < T; i++)
    {
        for (int j = 0; j < (2 ^ i); j++)
        {
            Matrix[i][j] = s0 * multiply(u, (2 ^ i) - j)*multiply(d, j);
        }
    }
    for (int i = 0; i < (int)Matrix.size(); i++)
    {
        for (int j = 0; j < (int)Matrix[i].size(); j++)
        {
            cout << Matrix[i][j] << "  ";
        }
        cout << endl;
    }
}