Finding the maximum value without using built-in functions
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My instructor assigned me a problem to solve, but unfortunately I couldn't, though I know it's an easy trick. I will write the program first, then I will ask the question:
n=input('Enter the number of the student: ');
for a=1:n
B(a)=input('Enter the grades as numerical values: ');
end
It's clear that variable B is a matrix containing the grades as numerical values. The problem that's assigned to me, is to find a way to show the biggest grade in the matrix without using MAX function or any other built-in functions, but rather by comparing the grades using for loop. It's like comparing the first grade with the other grades, and then the loop will keep assigning the bigger value each time the condition is verified.
I don't know how to do it although I have tried numerous times, so I would be thankful for your help.
采纳的回答
Leah
2011-5-13
I think sort counts as a built-in function. I assume all of your grades will be positive
n=input('Enter the number of the student: '); maxgrade=0; for a=1:n
B(a)=input('Enter the grades as numerical values: ');
if B(a) > maxgrade
maxgrade=B(a);
end
end
sprintf('Max Grade: %0.5g',maxgrade)
1 个评论
Sean de Wolski
2011-5-13
That was the point. Typically the question is "How can I find the max without using MAX"; the two examples I provided were cheap workarounds. However, this professor has also eliminated other built-ins, making them wise up to our awesomeness.
更多回答（3 个）
Andy
2011-5-13
0 个投票
Before the loop, create a variable called currMax, and set it equal to 0. Within the loop, with each grade that's entered, compare it to currMax. If it is bigger than currMax, then you can replace currMax with that new grade. Otherwise, do not replace currMax. There's not much more to say without doing your assignment for you.
3 个评论
Matt Tearle
2011-5-13
Slight improvement (IMHO): set currMax to the first element, then loop over the rest. (In this case we can assume all the values are positive, but not in general.)
Andy
2011-5-13
Fair enough, but if the class is receiving negative grades, then there are bigger problems than our mistaken assumption. :)
Sean de Wolski
2011-5-13
Initialize currMax to -inf, for Andy's method.
Sean de Wolski
2011-5-13
Those professors are wising up to the:
the_max = min(-x);
%or
s = sort(x);
the_max = s(end);
tricks...
1 个评论
Matt Tearle
2011-5-13
Fight back! This assignment, as stated ("any other built-in function"), is impossible! Proof:
which gt
edit gt
Abdullah
2011-5-13
0 个投票
1 个评论
Sean de Wolski
2011-5-13
just record a inside the if statement.
if B(a) > maxgrade
maxgrade=B(a);
idx = a;
end
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