LeftPad ( 注意：复用代码！！！)

Example:
leftpad("foo", 5)
" foo"

leftpad("foobar", 6)
"foobar"

leftpad("1", 2, "0")
"01"

public class StringUtils {
 /**
 * @param originalStr the string we want to append to with spaces
 * @param size the target length of the string
 * @return a string
 */
 static public String leftPad(String originalStr, int size) {
 // Write your code here
// 此方法中直接调用另一个版本的method，简单高效。
    return leftPad(originalStr, size, ' ');
 }

 /**
 * @param originalStr the string we want to append to
 * @param size the target length of the string
 * @param padChar the character to pad to the left side of the string
 * @return a string
 */
 static public String leftPad(String originalStr, int size, char padChar) {
 // Write your code here
    if (originalStr.length() >= size) {
        return originalStr;
    }
    
    int spaceLen = size - originalStr.length();
    String result = "";
    for (int i = 0; i < spaceLen; i++) {
        result = padChar + result;
    }
    
    return result + originalStr;
 }
}