References vs Pointers

References: Safer Aliases

A reference is another name for an existing variable. Unlike pointers, references cannot be null and cannot be reseated:

int x = 10;
int& ref = x;   // ref IS x — same memory

ref = 20;        // changes x!
cout << x;      // 20

const references — read-only, no copy

void printInfo(const string& name) {
    cout << name;   // can read, cannot modify
}                    // no copy of the string made!

When to use which

• const T& — read large objects cheaply
• T& — modify caller's variable
• T* — nullable, arrays, or when reassignment needed

Your Task

Write normalize(vector<double>& v) that divides every element by the maximum so the largest becomes 1.0. Modifies the vector in-place.