LintCode 左填充

题目

实现一个leftpad库，如果不知道什么是leftpad可以看样例

样例

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

代码

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
        int len = originalStr.length();
        StringBuilder sb = new StringBuilder();

        if (size <= len) return originalStr;
        else {
            for (int i = 0; i < size-len; i++) sb.append(" ");
            sb.append(originalStr);
        }
        return sb.toString();
    }

    /**
     * @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 len = originalStr.length();
        StringBuilder sb = new StringBuilder();

        if (size <= len) return originalStr;
        else {
            for (int i = 0; i < size-len; i++) sb.append(padChar);
            sb.append(originalStr);
        }
        return sb.toString();
    }
}