[LintCode] 524 Left Pad 解题报告

Description
You know what, left pad is javascript package and referenced by React.

One day his author unpublished it, then a lot of javascript projects in the world broken.

You can see from github it's only 11 lines. You job is to implement the left pad function.

If you do not know what left pad does, see examples below and guess.


Example
leftpad("foo", 5)
>> " foo"
leftpad("foobar", 6)
>> "foobar"
leftpad("1", 2, "0")
>> "01"


思路
看看要补几位，补进去就好了。


Code

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
        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
        int diff = size - originalStr.length();
        for (int i = 0; i < diff; i++) {
            originalStr = padChar + originalStr;
        }
        return originalStr;
    }
}