In every solution, present the following. Pseudocode. Look at our slides for examples. Try not to make pseudocode look like aprogram with unnecessary details. Pseudocodes should be short and easy to follow since theyare meant for humans $($not machines$).$ For instance, do not declare variables. Just use them.For swapping, write, swap A$[$i$]$ and A$[$j$],$ etc. But your pseudo$-$code must not be vague.Every step must be unambiguous. Concise explanation. Explain briefly how the idea behind your algorithm design. If youare using any math observation, you need to prove it$.$ Give a short example to illustrate. Efficiency analysis. Time and space complexities using Big$-$O$\mathrm{.}1.(5$ points$)$ You are given an array A of n integers. Assume that the array is notread$-$only. You can modify its content if needed. The integers in the array are takenfrom the set $\{1,2,...,$ n$\}.$ Every integer in the set appears in A except one. This meansexactly one integer from the set appears twice in A$.$ Design an algorithm to find themissing integer in O$($n$)$ time using O$(1)$ extra space. Side note: a brute$-$force algorithmfor the problem runs in O$($n$2)$ time. Using sorting one can bring down the runtime toO$($n log n$)$