message: Added InterviewBit probelm with sol
diff: Given an array of integers A, which is then assumed to be making a histogram with values of indexes in the array.
  The aim is to find the largest possible rectangle we could find from this histogram.
  This solution is a OPTIMAL solution written in cpp , similar concept could be applied to write this program in other languages.
  -This file only includes the helper function, you will need to write your own driver function if you're running the program on your local machine.
  TIME COMPLEXITY: O(n)
  SPACE COMPLEXITY: O(n)
  APPROACH:
  @@ -19,7 +18,11 @@ NOTE: for first element i.e. at index '0' left boundary is presumed -1
  This fits well with our width formula
  */
  -largestRectangleArea(vector<int> &A) {
  +#include <bits/stdc++.h>
  +using namespace std;
  +
  +// helper function
  +int largestRectangleArea(vector<int> &A) {
  int len = A.size();
  if(len == 0) return 0;
  @@ -66,3 +69,19 @@ largestRectangleArea(vector<int> &A) {
  }
  return rel;
  }
  +
  +// driver function
  +int main() {
  + int N;
  + // Enter the number of elements you want to register
  + cin>>N;
  + vector<int> input(N);
  + // Input
  + for(int i=0; i < N; i++) {
  + cin>>input[i];
  + }
  + // Answer
  + cout<<largestRectangleArea(input);
  + return 0;
  +}
  +
  