This chapter discussed searching and sorting data. We began by discussing searching. We first presented the simple, but inefficient linear search algorithm. Then, we presented the binary search algorithm, which is faster but more complex than linear search. Next, we discussed sorting data. You learned two simple, but inefficient sorting techniques—insertion sort and selection sort. Then, we presented the merge sort algorithm, which is more efficient than either the insertion sort or the selection sort. Throughout the chapter we also introduced Big O notation, which helps you express the efficiency of an algorithm by measuring the worst-case runtime of an algorithm. Big O is useful for comparing algorithms so that you can choose the most efficient one. In the next chapter, we discuss typical string-manipulation operations provided by class template basic_string. We also introduce string stream-processing capabilities that allow strings to be input from and output to memory.