Arrays and Iteration

Find Maximum

Scan the array once, keeping the largest value seen so far. The replay highlights when a candidate replaces the running maximum.

Algorithm

execution replay The checked-in replay follows the language-neutral state table for `array-find-max`.
cross-language comparison This C# DSA version keeps the same data and final output as every other DSA book in this wave.

Basic Implementation

basic.cs
Replay: real traced execution (multi-file project)
using System;

class Program {
	static void Main() {
		int[] arr = new int[] { 3, 1, 4, 1, 5, 9, 2, 6 };
		int best = arr[0];
		for (int i = 1; i < arr.Length; i++) {
			if (arr[i] > best) {
				best = arr[i];
			}
		}
		Console.WriteLine(best);
	}
}

  1. arr ← [3, 1, 4, 1, 5, 9, 2, 6], best ← 3

    1using System;
    values this step[3, 1, 4, 1, 5, 9, 2, 6]arr3best

  2. replaced ← no

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this stepnoreplaced1i1arr[i]3best

  3. best ← 4, replaced ← yes

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this step3 → 4bestyesreplaced2i4arr[i]

  4. replaced ← no

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this stepnoreplaced3i1arr[i]4best

  5. best ← 5, replaced ← yes

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this step4 → 5bestyesreplaced4i5arr[i]

  6. best ← 9, replaced ← yes

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this step5 → 9bestyesreplaced5i9arr[i]

  7. replaced ← no

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this stepnoreplaced6i2arr[i]9best

  8. replaced ← no

    7for (int i = 1; i < arr.Length; i++) {8	if (arr[i] > best) {9		best = arr[i];
    values this stepnoreplaced7i6arr[i]9best

  9. stdout ← 9

    1using System;
    values this step9stdout9best

Complexity

  • Time: O(n)
  • Space: O(1)

Implementation notes

  • Keep the explicit control flow. Library shortcuts would hide the state changes this lesson is meant to replay.
  • The int[] is a managed reference type: the CLR owns allocation and GC, and every arr[i] read is bounds-checked at runtime. The loop uses arr.Length instead of sentinel values or pointer arithmetic, keeping the scan safe while still exposing each comparison in the replay.