left at 0 and right at the length of the string minus 1.left is less than right:
a. If the characters at left and right are different, break the loop.
b. Store the character at left in a variable c.
c. Increment left while the next character is the same as c.
d. Decrement right while the previous character is the same as c and left is not greater than right.left to right, which is right - left + 1.