剑指 Offer 05. 替换空格

class Solution {
    public String replaceSpace(String s) {
        StringBuffer sb = new StringBuffer();
        for(int i=0;i<s.length();i++) {
            char c = s.charAt(i);
            if(c != ' ') {
                sb.append(c);
            }else{
                sb.append("%20");
            }
        }
        return sb.toString();
    }
}