Finding the largest number in a list of numbers

What is the largest number in this list of numbers?

23	45	26	19	48	74	68	43
57	30	44	28	50	60	38	23
94	47	83	91	72	77	76	55
82	11	32	31	58	21	40	80
56	88	41	13	70	41	53	62
21	62	78	95	37	58	61	82
18	43	12	17	83	65	20	90
71	77	10	51	35	91	59	52
27	58	65	74	88	42	63	32
87	33	72	64	18	15	58	27

How did you find it?

• Did you compare the first number with each of the other numbers? Then did you compare the second number to each of the other numbers? Then did you compare the third number to each of the other numbers? etc...
• Did you write down all the numbers in ascending order and then take the last number as the largest?
• Did you just skip looking for the largest number and continued to read, looking for the answer in this paragraph? If so, then go back and find the largest number!

I think that what you did was this: you looked at each number once and you remembered the largest that you had seen up to that point. After you had looked at all the numbers, then you knew which one was the largest.

There is another point to make: you initialized the largest number with the first number in the list.

This same method can be applied in a program.

• Read the first number from the user.
• Set the LargestSoFar variable to the first number.
• Use a loop to read the remaining numbers from the user, comparing each new number with the LargestSoFar.
• If the new number is larger, then set LargestSoFar to the new number.
• After you have read all the numbers, then LargestSoFar will be the largest number read.

Using this technique in the above list:

Read the first number and set LargestSoFar equal to it.

LargestSoFar

23

In a loop, read each NewNumber, and compare it to LargestSoFar. If NewNumber is greater than LargestSoFar, then set LargestSoFar to the NewNumber.

LargestSoFar	NewNumber
23	45
45 (changed)	26
45	19
45	48
48 (changed)	74
74 (changed)	68
74	43
74	57
etc...	etc...