Fix #822 added Binary Search[CPP]

[varunvilva]

Fixes #822

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Output:

[varunvilva]

I am taking the index number as the input for the function binary search. So it will not produce overflow.If in input high is taken as array length then it will cause overflow. I have also seen some codes use mid = low + (high - low) /2 are you referring to this as overflow?

[kalashshah]

Yes mid = (low + high) / 2 can cause overflow