# finding the min and max values in an array

Could anybody give me an efficient algorithm for finding the min and max values in an unsorted array. Its not just one array that i have to process, but it may be about 20000 arrays. There is 1 min and the 1 max is for all the arrays together.
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Commented:
Since the array is unsorted, you would have to go through every item in the array:

int min = Integer.MAX_VALUE;
int max = Integer.MIN_VALUE;
for (int i = 0; i < yourArray.length; i++) {
min = yourArray[i] < min ? yourArray[i] : min;
max = yourArray[i] > max ? yourArray{i] : max;
}
System.out.println("Min = " + min);
System.out.println("Max = " + max);
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Commented:
yongsing is right. you have to check every value. but if you wrap a controller type class around all your arrays could limit the amount of searching you have to do. That way you would only have to check the min/max on addition, removal(if the array contained a min or max), or alteration of the data in the underlying arrays ( which you could control in the accessor as well ).
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Commented:
youngsing's code is wrong!!!!!!!!!!!!!!!!!

int min = Integer.MAX_VALUE;
int max = Integer.MIN_VALUE;
for (int i = 0; i < yourArray.length; i++) {
min = yourArray[i] < min ? yourArray[i] : min;
max = yourArray[i] > max ? yourArray{i] : max;
}
System.out.println("Min = " + min);
System.out.println("Max = " + max);

/********************************************/
NO INTEGER WILL BE LESS THAN min(Integer.MIN_VALUE).
HE SHOULD HAVE INITIALIZED IT AS

int min = yourArray[0] ;
int max = yourArray[0] ;

/*************************************************/

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Commented:
>> NO INTEGER WILL BE LESS THAN min(Integer.MIN_VALUE).

That's true. I never claim that any integer will be less than Integer.MIN_VALUE. My code still works.
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Commented:
suppose his array contains

min value of -1000
and max value of +1000

ur code will work but it will show
max=Integer.MAX_VALUE;
min=Integer.MIN_VALUE;

not
max=1000
min=-1000

because
1000!>Integer.MAX_VALUE  //max = yourArray[i] > max ? yourArray{i] : max;

-1000!<Integer.MIN_VALUE //min = yourArray[i] < min ? yourArray[i] : min;

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Commented:
Well, why don't you try this:

public class TestMinMax {

public static void main(String[] args){
int[] yourArray = {0, -1, 345, -45, 1000, -666, -1000, 234};
int min = Integer.MAX_VALUE;
int max = Integer.MIN_VALUE;
for (int i = 0; i < yourArray.length; i++) {
min = yourArray[i] < min ? yourArray[i] : min;
max = yourArray[i] > max ? yourArray[i] : max;
}
System.out.println("Min = " + min);
System.out.println("Max = " + max);
}
}

It prints:

Min = -1000
Max = 1000

Perhaps you're convinced now.
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Author Commented:
The answer that yongsing has given (and i accepted it as the answer) works fine
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Commented:
hi youngsing
i am sorry man!
ur code works because

int min = Integer.MAX_VALUE;//here min is equal to MAX
int max = Integer.MIN_VALUE;//here max is equal to MIN

i did not notice this swapping nor did u point this out in
i regret it.
regards
swargdwar

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Commented:
No problem, swargdwar. :) In fact, initializing the min and max variables to the first element of the array might be a better idea, because it's not that confusing.
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