编程之美----最短摘要的生成

 1 #include <stdio.h>
 2 #include<map>
 3 #include<string>
 4 
 5 using namespace std;
 6 
 7 int main()
 8 {
 9 
10     char keyword[][3] = {"q0", "q1"};
11     char description[][3] = {"w0","w1","w2","w3","q0","w4","w5",
12                         "q1","w6","w7","w8","q0","w9","q1"};
13 
14     int kLen = sizeof(keyword)/sizeof(keyword[0]);
15     int dLen = sizeof(description)/sizeof(description[0]);
16     int N = dLen;
17 
18     int nTargetLen = N + 1; //设置目标长度为总长度加1
19     int pBegin = 0;         //初始指针
20     int pEnd = 0;           //结束指针
21     int nLen = N;           //目标数组的长度为N
22     int nAbstractBegin = 0; //目标摘要的起始地址
23     int nAbstractEnd = 0;   //目标摘要的结束地址
24     int cnt = 0;            //记录出现关键词的
25 
26     map<string, int> times; //记录各个关键词出现的次数
27     for(int i = 0; i < kLen; i++)
28     {
29         times[string(keyword[i])] = 0;
30     }
31 
32     while(1)
33     {
34         //假设包含所有的关键词，并且后面的指针没有越界，往后移动指针
35         while(cnt != kLen && pEnd < nLen)
36         {
37             if(times.count(description[pEnd]))
38             {
39                 if(times[description[pEnd]] == 0)
40                 {
41                     cnt++;
42                 }
43                 times[description[pEnd]]++;
44             }
45             pEnd++;
46         }
47 
48         while(cnt == kLen)
49         {
50             if(pEnd - pBegin < nTargetLen)
51             {
52                 nTargetLen = pEnd - pBegin;
53                 nAbstractBegin = pBegin;
54                 nAbstractEnd = pEnd - 1;//此处减一是因为45行多加了一个1
55             }
56 
57             if(times.count(description[pBegin]))
58             {
59                 if(--times[description[pBegin]] == 0)
60                 {
61                     cnt--;
62                 }
63             }
64             pBegin++;
65         }
66 
67         if(pEnd >= N)
68             break;
69     }
70 
71     for(int i = nAbstractBegin; i <= nAbstractEnd; i++)
72     {
73         printf("%s ",description[i]);
74     }
75     return 0;
76 }