识别有效的IP地址和掩码并进行分类统计

该题我的想法是把每一个ip看出一个整数，将读取得到的数据一一与给定的ip范围比较即可。另外本题应该注意的地方是scanf读取俩字符串的方法。

代码如下：

 #include<stdio.h>
 #include<string.h>
 #include<iostream>
 using namespace std;

 unsigned long long range[][] = {
     {,},
     {,},
     {,},

     {,},
     {,},
     {,},
     {,},
     {,},
 };

 int explain(char* ip){
      int expect = ;
      int cnt = ;
      for(int i =  ; i < strlen(ip) ; i ++){

         if(ip[i] >= '' && ip[i] <= ''){
             expect = ;
         }
         else{
             if(expect == ) return -;
             expect = ;//下一个字符必须是数字
             cnt ++;
         }
      }
     if(cnt != ) return -;// 必须有三个.符号
     return  ;
 }

 int main(){
     char ip[] , code[];
     int a =  , b =  , c =  , d =  , e =  ,eip =  , sip = ;
     int cnt = ;
     while(scanf("%[^~]~%s",ip,code) != EOF){
         int cds = explain(code);
         int flag = ;
         if(cds > ){
              int aa[];
              sscanf(code , "%d.%d.%d.%d" , &aa[],&aa[],&aa[],&aa[]);
             if(aa[] >  || aa[] >  || aa[] >  || aa[] >  || (aa[] ==  && aa[] ==  && aa[] == &&aa[]== )){
             //qudiao 255.255.255.255 以及在某个位上大于255的不合法的mask
                 eip ++;
                 flag = ;
             }
             int exp = ;
             for(int i =  ; !flag && i <  ; i ++){
                 if(exp ==  && aa[i] || aa[i] > ){
                     eip ++;
                     flag = ;
                     break;
                 }
                 int a1 = aa[i];
                 if(a1 < ){
                     if(a1 ==  || a1 ==  || a1 ==  || a1 ==  || a1 ==  || a1 ==  || a1 == ){
                         exp = ;
                     }else if(a1 ==  && i > ){
                         exp = ;//去除0.0.0.0
                     }
                     else{
                         eip ++;
                         flag = ;
                         break;
                     }
                 }
            }
         }else{
             flag = ;
             eip ++;
         }//end
         if(flag == ){
             int ips = explain(ip);
             if(ips > ){

                 int a1 , b1 ,c1 ,d1;
                 sscanf(ip , "%d.%d.%d.%d" , &a1,&b1,&c1,&d1);
                 if(a1> || b1 >  || c1 >  || d1 > ){
                     eip++;
                     flag = ;
                 }
                 if(flag == ){
                     long long ans = a1*1e9 + b1*1e6 + c1*1e3 + d1;
                     //cout<<ans<<endl;
                     int i = ;
                     for( ; i <  ; i ++){
                         if(ans <= range[i][] && ans >= range[i][]){
                             // cout<<i<<endl;
                             if(i == ) a ++;
                             if(i == ) b ++;
                             if(i == ) c ++;
                             if(i == ) d ++;
                             if(i == ) e ++;
                             if(i ==  || i ==  || i == ) sip ++;
                             //break;
                         }
                     }
                 }
             }else{
                 eip ++;
             }
         }
        memset(ip,'\0',sizeof ip);
        memset(code,'\0',sizeof(code));
        getchar();
     }
     printf("%d %d %d %d %d %d %d\n",a,b,c,d,e,eip,sip);
     return ;
 }