<p>Write a method to replace all spaces in a string with '%20'. You may assume that the string has sufficient space at the end to hold the additional characters,and that you are given the "true" length of the string. (Note: If implementing in Java,please use a character array so that you can perform this operation in place.)</p> <p><strong>Example 1:</strong></p> <pre> <strong>Input: </strong>"Mr John Smith ", 13 <strong>Output: </strong>"Mr%20John%20Smith" </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input: </strong>" ", 5 <strong>Output: </strong>"%20%20%20%20%20" </pre> <p> </p> <p><strong>Note:</strong></p> <ol> <li><code>0 <= S.length <= 500000</code></li> </ol>