力扣打卡第一天 交替合并字符串

力扣打卡第一天 交替合并字符串

class Solution {
    public String mergeAlternately(String word1, String word2) {
      int len1 = word1.length(), len2 = word2.length();
      StringBuffer res = new StringBuffer();
      int i = 0, j = 0;
      for(int k = 0; k<len1+len2; k++){
        if(i<len1 && j<len2){
          if(k%2 == 0){
            res.append(word1.charAt(i));
            i++;
          } else {
            res.append(word2.charAt(j));
            j++;
          }
        } else if(i==len1){
          res.append(word2.charAt(j));
          j++;
        } else{
          res.append(word1.charAt(i));
          i++;
        }
      }
      return res.toString();
    }
}