剑指 Offer 05. 替换空格

class Solution {
    public String replaceSpace(String s) {
        int length = s.length();
        char[] array = new char[length * 3];
        int size = 0;
        for (int i = 0; i < length; i++) {
            char c = s.charAt(i);
            if (c == ' ') {
                array[size++] = '%';
                array[size++] = '2';
                array[size++] = '0';
            } else {
                array[size++] = c;
            }
        }
        String newStr = new String(array, 0, size);
        return newStr;
    }
}

public class ReplaceSpace {

    public static String replaceSpace(StringBuffer str) {
        if(str == null){
            return null;
        }
        StringBuilder res = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i) == 0x20){
                res.append("%20");
            }else{
                res.append(str.charAt(i));
            }
        }
        return res.toString();
    }

    public static void main(String[] args) {
        System.out.println(replaceSpace(new StringBuffer("We are happy")));
    }
}