the below code is a c++ program that calculates the sum of the letters in given text.

#include <iostream>
using namespace std;

int letter_sum(string text)
{
    int Psum = 0;
    int n;
    while (text[n] != '')
    {
        n++;
        Psum = Psum + text [n];
    }
    int Rsum = Psum - (96*n);
    return Rsum;
}

int main ()
{
    string text;
    cout << "type the text: ";
    cin >> text;
    int displayvalue =letter_sum(text);
    cout << displayvalue << endl;
}

as per output I was expecting a num(which is sum of letters in given text ofcourse), but I got a error message showing segmentation fault.im a beginner to coding.so please explain in some easy terms and if possible tell me how to solve this problem.