判断 ACdream 1202 Integer in C++

题目传送门

 /*
     分情况讨论，在long long范围里可以直接比较
     sscanf 直接读到n中去
 */
 #include <cstdio>
 #include <iostream>
 #include <string>
 #include <algorithm>
 #include <cstring>
 #include <map>
 #include <set>
 #include <vector>
 using namespace std;

 const int MAXN = 1e4 + ;
 const int INF = 0x3f3f3f3f;

 int main(void)        //ACdream 1202 Integer in C++
 {
     //freopen ("G.in", "r", stdin);

     string s;    string s_max = "";
     while (cin >> s)
     {
         long long n;
         int len = s.size ();
         if (s[] != '-')
         {
             if (len < )
             {
                 sscanf (s.c_str (), "%lld", &n);
                 if (n <= )    cout << "short" << endl;
                 else if (n <= )    cout << "int" << endl;
                 else    cout << "long long" << endl;
             }
             else if (len == )
             {
                 if (s > s_max)    cout << "It is too big!" << endl;
                 else cout << "long long" << endl;
             }
             else    cout << "It is too big!" << endl;
         }
         else
         {
             if (len < )
             {
                 sscanf (s.c_str (), "%lld", &n);
                 if (n >= -)    cout << "short" << endl;
                 else if (n >= )    cout << "int" << endl;
                 else    cout << "long long" << endl;
             }
             else if (len == )
             {
                 s.erase (s.begin ());
                 if (s < s_max)    cout << "long long" << endl;
                 else    cout << "It is too big!" << endl;
             }
             else    cout << "It is too big!" << endl;
         }
     }

     return ;
 }

 /*
 -32768 to 32767
 -2147483648 to 2147483647
 -9223372036854775808 to 9223372036854775807
 short, int, long long
 It is too big!
 */

 /*
     for循环保存n
     注意：2147483647 + 1 -> -2147483648，-2147483648 > 2147483647
         在二进制中并不是数学的比大小
 */
 #include <cstdio>
 #include <iostream>
 #include <string>
 #include <algorithm>
 #include <cstring>
 #include <map>
 #include <set>
 #include <vector>
 using namespace std;

 const int MAXN = 1e4 + ;
 const int INF = 0x3f3f3f3f;

 int main(void)        //ACdream 1202 Integer in C++
 {
     freopen ("G.in", "r", stdin);

     string s;
     char ss[], ss_ll1[] = "", ss_ll2[] = "";

     while (scanf ("%s", &ss) == )
     {
         int len = strlen (ss);    long long n;
         if (len > )    puts ("It is too big!");
         else if (ss[] == '-')
         {
             if (len == )
             {
                 if (strcmp (ss+, ss_ll1) <= )    puts ("long long");
                 else    puts ("It is too big!");
             }
             else if (len < )
             {
                 n = ;
                 for (int i=; i<len; ++i)    n = n *  + (ss[i] - '');
                 n = -n;
                 if (n >= - && n <= )    puts ("short");
                 else if (n >= - && n <= )    puts ("int");
                 else    puts ("long long");
             }
         }
         else if (len <= )
         {
             if (len == )
             {
                 if (strcmp (ss, ss_ll2) <= )    puts ("long long");
                 else    puts ("It is too big!");
             }
             else
             {
                 n = ;
                 for (int i=; i<len; ++i)    n = n *  + (ss[i] - '');
                 if (n >= - && n <= )    puts ("short");
                 else if (n <=  && n >= -)    puts ("int");
                 else    puts ("long long");
             }
         }
         else    puts ("It is too big!");
     }

     return ;
 }

 /*
 -32768 to 32767
 -2147483648 to 2147483647
 -9223372036854775808 to 9223372036854775807
 short, int, long long
 It is too big!
 */