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Just a very silly thing, but you can also use Short values for the purpose of this problem, it doesn't have to be necessarily an Integer. Just for using less memory. :)

Very large negative values are not necessary. See that an hourglass is made up of 7 digits. the sum of 'those' 7 digits can be minimum when each digit is itself minimum, i.e, -9. Hence, the minimum sum will be (7)x(-9), which equals -63. So, we can initialize minimum as -64

Given the constraint in the question (-9 <= arr[i][j] <= 9 and 0 <= i,j <= 5), I used the possible maximum negative value to initialize my max value (-9 * 6 = -54).

This is correct, but the test cases given also had nothing lower than -54, which was lucky for me, since I made the (mindless) error of thinking there were only 6 elements in an hourglass.

One of the test cases should have a max of -62 for this reason, IMO.

This is correct. Given the question the lowest possible sum is -63. The sum of an hourglass is always multiplied by 7 (2 rows of 3 + 1 column of 1). The highest negative number is -9. Therefore -9 * 7 = -63

Very large negative values are not necessary. See that an hourglass is made up of 7 digits. the sum of 'those' 7 digits can be minimum when each digit is itself minimum, i.e, -9. Hence, the minimum sum will be (7)x(-9), which equals -63. So, we can initialize minimum as -64.

## 2D Array - DS

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Just a very silly thing, but you can also use Short values for the purpose of this problem, it doesn't have to be necessarily an Integer. Just for using less memory. :)

I think the input variables are defined as primitive type int.

But that doesn't mean you cannot change. At the end the output is a string, so it doesn't matter.

Guys we also have one more alternative, with the help of flag we can achieve it,

if (flag) {

max = sum;

flag = false;

}

if (max < sum) {

max = sum;

}

will it not give a compilation error i.e max is not initialized or something like that?

or in JS:

let max;

if (typeof max !== 'number' || sum > max) { max = sum }

I used, max = -Infinity

Very large negative values are not necessary. See that an hourglass is made up of 7 digits. the sum of 'those' 7 digits can be minimum when each digit is itself minimum, i.e, -9. Hence, the minimum sum will be (7)x(-9), which equals -63. So, we can initialize minimum as -64

you could actually initialize it with -63 ,would still work.

In JS, I used

let maxSum = Number.MIN_SAFE_INTEGER;

Using your logic, you could use the type byte.

In Java you could use byte, since it is signed. In C# byte is an unsigned type and not appropriate.

To store the numbers you really only need 7 bits, but there's little use in packing these arrays.

Given the constraint in the question (-9 <= arr[i][j] <= 9 and 0 <= i,j <= 5), I used the possible maximum negative value to initialize my max value (-9 * 6 = -54).

max negative value is -63 (-9 * 7)

anything less than -54.

For python initialize with: -9223372036854775807

I initialized with 1 << 16 * -1

That would very silly. Why not just use the minimum value of -63 as others have indicated.

This is correct, but the test cases given also had nothing lower than -54, which was lucky for me, since I made the (mindless) error of thinking there were only 6 elements in an hourglass.

One of the test cases should have a max of -62 for this reason, IMO.

This is correct. Given the question the lowest possible sum is -63. The sum of an hourglass is always multiplied by 7 (2 rows of 3 + 1 column of 1). The highest negative number is -9. Therefore -9 * 7 = -63

first value always works and doesn't rely on you knowing the input before execution

yes intitalizing max value less than maximum negative value helped me in solving 3,5,7 testcases

Very large negative values are not necessary. See that an hourglass is made up of 7 digits. the sum of 'those' 7 digits can be minimum when each digit is itself minimum, i.e, -9. Hence, the minimum sum will be (7)x(-9), which equals -63. So, we can initialize minimum as -64.

as a[i][j]>=-9 so just initialize the min value to -9*7 as hour glass consiste of 7 elements and considering worst case for least sum all would be -9

Well if you will analyze inuts then you will get the idea. no array value can be < -9. it means [(-9 *3 *2)+-(9)] . this is your lowest value