CSCI-1200/lectures/04_pointers/README.md

Lecture 4 --- Pointers, Arrays, & Pointer Arithmetic

• Pointers store memory addresses.
• They can be used to access the values stored at their stored memory address.
• They can be incremented, decremented, added, and subtracted.
• Dynamic memory is accessed through pointers.
• Pointers are also the primitive mechanism underlying vector iterators, which we have used with std::sort and will use more extensively throughout the semester.

4.1 Pointer Example

• Consider the following code segment:

float x = 15.5;
float *p; /* equiv: float* p; or float * p; */
p = &x;
*p = 72;
if ( x > 20 )
cout << "Bigger\n";
else
cout << "Smaller\n";

The output is Bigger because x == 72.0. What’s going on?

4.2 Exercises

• Leetcode problem 905: Sort Array By Parity. Solution: p905_sortarraybyparity.cpp
• Leetcode problem 977: Squares of a Sorted Array. Solution: p977_sortedsquare.cpp
• Leetcode problem 1051: Height Checker. Solution: p1051_heightchecker.cpp