String Window STL problem

#1

Approach for string window problem?

#2
  • Approach: Basically a window of characters is maintained by using two variables namely start and end . These start and end pointers can be used to shrink and increase the size of window respectively. Whenever the window contains all characters of given string, the window is shrinked from left side to remove extra characters and then its length is compared with the smallest window found so far.
    If in the present window, no more characters can be deleted then we start increasing the size of the window using the end until all the distinct characters present in the string are also there in the window. Finally, find the minimum size of each window.