bool cmp(string a,string b){ int la=a.length(),lb=b.length(); int i=0; while(i<la&&i<lb){ if(a[i]!=b[i])return a[i]>b[i]; i++; } if(i<la)return cmp(a.substr(i,la-1),b); if(i<lb)return cmp(a,b.substr(i,lb-1)); }求大佬指教