poj2264 dp+路径

 1 //Accepted    208K    0MS
 2 //dp
 3 //最长公共子序列+路径
 4 #include <cstdio>
 5 #include <cstring>
 6 #include <iostream>
 7 using namespace std;
 8 const int imax_n = 105;
 9 const int inf = 100000000;
10 int dp[imax_n][imax_n];
11 char s1[imax_n],s2[imax_n];
12 int l1,l2;
13 int max(int a,int b)
14 {
15     return a>b?a:b;
16 }
17 void Dp()
18 {
19     memset(dp,0,sizeof(dp));
20 
21     for (int i=1;i<=l1;i++)
22     {
23         for (int j=1;j<=l2;j++)
24         {
25             //dp[i][j]=inf;
26             dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
27             if (s1[i-1]==s2[j-1])
28             dp[i][j]=max(dp[i][j],dp[i-1][j-1]+1);
29         }
30     }
31     //printf("%d\n",dp[l1][l2]);
32 }
33 void output(int i,int j)
34 {
35     if (dp[i][j]==0)
36     {
37         for (int k=1;k<=i;k++)
38         printf("%c",s1[k-1]);
39         for (int k=1;k<=j;k++)
40         printf("%c",s2[k-1]);
41         return ;
42     }
43     if (dp[i][j]==dp[i-1][j-1]+1 && s1[i-1]==s2[j-1])
44     {
45         output(i-1,j-1);
46         printf("%c",s1[i-1]);
47         return ;
48     }
49     if (dp[i][j]==dp[i-1][j])
50     {
51         output(i-1,j);
52         printf("%c",s1[i-1]);
53         return ;
54     }
55     if (dp[i][j]==dp[i][j-1])
56     {
57         output(i,j-1);
58         printf("%c",s2[j-1]);
59         return ;
60     }
61 }
62 int main()
63 {
64     while (scanf("%s%s",s1,s2)!=EOF)
65     {
66         l1=strlen(s1);
67         l2=strlen(s2);
68         Dp();
69         output(l1,l2);
70         printf("\n");
71     }
72     return 0;
73 }