Update 3_Solution.sol

[ankit957173]

for index out of bound if index provided should be larger than array length and in require index should be smaller than array length

[kanian]

It's

if (_index > arr.length - 1) {
            return;
        }

Let's say arr.length = 6; If you say _index > arr.length, you will get the case where _index = 6, which is clearly out of bounds, but with ( _index > arr.length ) == false;