1768. 交替合并字符串

class Solution {
public:
    string mergeAlternately(string word1, string word2) {
            int len1=word1.size();
            int len2=word2.size();
            int c=min(len1,len2);
            
        
            string x="";
       
            for(int i=0;i<c;i++)
            {
                    x+=word1[i];
                    x+=word2[i];
            }
            if(len1>len2){
                     x+=word1.substr(c, len1);
            }else
            {
                     x+=word2.substr(c, len2);
            }
            return x;
           
    }
};