1、s[i]=t[i];2、s[i]='\0';3、len2;4、strcopy(s,s2+i,len1);5、substring(s1,s2);编译了下，没有问题，希望能采纳
//1.s[i] = t[i];//2s[i] = '\0';//3(len2/len1)//4strcopy( s, s2+i, len1 );//5substring( s1, s2 );
