1 #include <iostream>
  2 using namespace std;
  3
  4
  5 // 编程题第一题
  6 // 识别输入字符串中所有的整数，统计整数个数并将这些字符串形式的整数转换为数字形式整数
  7 void take_num(const char *strIn, int *n, unsigned int *outArray)
  8 {
  9     unsigned int len = strlen(strIn);
 10     unsigned int outArrayIndex = 0;
 11     bool hasNumber = false; // temp 中已经存在有效数字
 12     unsigned int temp = 0;
 13     *n = 0;
 14     for(unsigned int i = 0; i < len; ++i)
 15     {
 16         if(strIn[i] >= '0' && strIn[i] <= '9')
 17         {
 18             if(hasNumber == false)
 19             {
 20                 // 间隔后第一次出现的数字
 21                 ++*n;
 22             }
 23             else
 24             {
 25                 // 连续出现的数字
 26             }
 27             hasNumber = true;
 28             temp = temp * 10 + (strIn[i] - '0');
 29         }
 30         else
 31         {
 32             if(hasNumber)
 33             {
 34                 outArray[outArrayIndex++] = temp;
 35                 temp = 0;
 36                 hasNumber = false;
 37             }
 38         }
 39     }
 40     if(hasNumber)
 41     {
 42         outArray[outArrayIndex++] = temp;
 43     }
 44 }
 45
 46
 47 // 编程题第二题
 48 // IP地址最长匹配问题，要求不仅是匹配，而且是最长匹配
 49 void max_prefix_match(const char *ip_addr, const char *net_addr_array[], int *n)
 50 {
 51     int arrayIndex = 0;
 52     *n = -1;
 53     const char* p = net_addr_array[arrayIndex];
 54     int maxLength = -1; //记录最长匹配串最远的1的位置
 55     int number = 0;// 用于转换字符串形式的点分十进制数至整数
 56     //先把IP址址转换成int型元素的数组
 57     int ipAddress[4];
 58     int netIndex = 0;
 59     int ipLen = strlen(ip_addr);
 60     for(int i = 0; i <= ipLen; ++i)
 61     {
 62         if(ip_addr[i] >= '0' && ip_addr[i] <= '9')
 63         {
 64             number = number * 10 + (ip_addr[i] - '0');
 65         }
 66         else
 67         {
 68             ipAddress[netIndex++] = number;
 69             number = 0;
 70         }
 71     }
 72     while(*p != '\0')
 73     {
 74
 75         int netAddress[4];//子网地址
 76         int maskAddress[4];//子网掩码
 77         netIndex = 0;
 78         //将点分十进制转成4个int元素
 79         int len = strlen(p); // 本次 IP地址/子网掩码 字符串的长度
 80         number = 0;
 81         int i;
 82         //先转换给定的子网地址
 83         for(i = 0; ; ++i)
 84         {
 85             if(p[i] >= '0' && p[i] <= '9')
 86             {
 87                 number = number * 10 + (p[i] - '0');
 88             }
 89             else
 90             {
 91                 netAddress[netIndex++] = number;
 92                 number = 0;
 93                 if(p[i] == '/')
 94                 {
 95                     netIndex = 0;
 96                     break;
 97                 }
 98             }
 99         }
100
101         //再转换子网掩码
102         for(++i; i <= len; ++i)
103         {
104             if(p[i] >= '0' && p[i] <= '9')
105             {
106                 number = number * 10 + (p[i] - '0');
107             }
108             else
109             {
110                 maskAddress[netIndex++] = number;
111                 number = 0;
112             }
113         }
114         netIndex = 0;
115
116         //判断IP地址和子网掩网的与 是否 和 子网地址相同
117         int j = 0;
118         for(;j < 4; ++j)
119         {
120             if((ipAddress[j] & maskAddress[j]) != netAddress[j])
121             {
122                 break;
123             }
124         }
125         if(j >= 4)
126         {
127             //匹配
128             //再比较长度，从最后往前数，记录下第一个出现1的位置
129             int currentLength = 0;
130             for(int k = 3; k >= 0; --k)
131             {
132                 if(netAddress[k] != 0)
133                 {
134                     currentLength = k * 8;
135                     // 将十进制转成二进制
136                     char binaryArray[8];
137                     int temp = netAddress[k];
138                     int index = 0;
139                     while(temp > 0)
140                     {
141                         if(temp % 2 == 0)
142                         {
143                             binaryArray[index++] = '0';
144                         }
145                         else
146                         {
147                             binaryArray[index++] = '1';
148                         }
149                         temp /= 2;
150                     }
151                     while(index <= 7)
152                     {
153                         binaryArray[index++] = '0';
154                     }
155                     for(int k = 0; k < 8; ++k)
156                     {
157                         if(binaryArray[k] == '1')
158                         {
159                             currentLength += (8 - k);
160                             break;
161                         }
162                     }
163                     break;
164                 }
165             }
166             if(currentLength > maxLength)
167             {
168                 maxLength = currentLength;
169                 *n = arrayIndex;
170             }
171         }
172         //输入下一个数组
173         ++arrayIndex;
174         p = net_addr_array[arrayIndex];
175     }
176 }
177
178
179 // 输出
180 void output(unsigned int* a, unsigned int len)
181 {
182     for(unsigned int i = 0; i < len; ++i)
183     {
184         cout << a[i] << " ";
185     }
186     cout << endl;
187 }
188
189 int main()
190 {
191     cout << "第一题测试样例：" << endl;
192     char *strIn = "ab00cd+123fght456-25  3.005fgh";
193     unsigned int outArray[100];
194     int n;
195     take_num(strIn, &n, outArray);
196     output(outArray, n);
197
198     cout << endl << "第二题测试样例：" << endl;
199     const char* ip_addr = "192.168.1.100";
200     const char *net_addr_array[] =
201     {
202         "192.168.1.128/255.255.255.192",
203         "192.168.1.0/255.255.255.0",
204         "192.168.1.64/255.255.255.192",
205         "0.0.0.0/0.0.0.0",
206         ""
207     };
208     max_prefix_match(ip_addr, net_addr_array, &n);
209     cout << n << endl;
210 }