1      /*功能：计算最优值
 2       *参数：
 3       *        x:字符串x  X:字符串x最大长度
 4       *        y:字符串y   Y:字符串y最大长度
 5       *        b:标志数组
 6       *        xlen:字符串x的长度
 7       *        ylen:字符串y的长度
 8       *返回值：最长公共子序列的长度
 9       *
10       */
11      int Lcs_Length(string x, string y, int b[][Y+1],int xlen,int ylen)
12      {
13          int i = 0;
14          int j = 0;
15
16          int c[X+1][Y+1];
17          for (i = 0; i<=xlen; i++)
18          {
19              c[i][0]=0;
20          }
21          for (i = 0; i <= ylen; i++ )
22          {
23              c[0][i]=0;
24          }
25          for (i = 1; i <= xlen; i++)
26          {
27
28              for (j = 1; j <= ylen; j++)
29              {
30                  if (x[i - 1] == y[j - 1])
31                  {
32                      c[i][j] = c[i-1][j-1]+1;
33                      b[i][j] = 1;
34                  }
35                  else
36                      if (c[i-1][j] > c[i][j-1])
37                      {
38                          c[i][j] = c[i-1][j];
39                          b[i][j] = 2;
40                      }
41                      else
42                          if(c[i-1][j] <= c[i][j-1])
43                          {
44                              c[i][j] = c[i][j-1];
45                              b[i][j] = 3;
46                          }
47
48              }
49          }
50
51          cout << "计算最优值效果图如下所示：" << endl;
52          for(i = 1; i <= xlen; i++)
53          {
54              for(j = 1; j < ylen; j++)
55              {
56                  cout << c[i][j] << " ";
57              }
58              cout << endl;
59          }
60
61          return c[xlen][ylen];
62      }

    //只能打印一个最长公共子序列#include <iostream>using namespace std;const int X = 1000, Y = 1000;        //串的最大长度char result[X+1];                    //用于保存结果int count=0;                        //用于保存公共最长公共子串的个数int c[X+1][Y+1];int b[X + 1][Y + 1];/*功能：计算最优值*参数：*        x:字符串x*        y:字符串y*        b:标志数组*        xlen:字符串x的长度*        ylen:字符串y的长度*返回值：最长公共子序列的长度**/int Lcs_Length(string x, string y, int b[][Y+1],int xlen,int ylen){int i = 0;int j = 0;//int c[X+1][Y+1];for (i = 0; i<=xlen; i++){c[i][0]=0;}for (i = 0; i <= ylen; i++ ){c[0][i]=0;}for (i = 1; i <= xlen; i++){for (j = 1; j <= ylen; j++){if (x[i - 1] == y[j - 1]){c[i][j] = c[i-1][j-1]+1;b[i][j] = 1;}elseif (c[i-1][j] > c[i][j-1]){c[i][j] = c[i-1][j];b[i][j] = 2;}elseif(c[i-1][j] <= c[i][j-1]){c[i][j] = c[i][j-1];b[i][j] = 3;}}}/*cout << "计算最优值效果图如下所示：" << endl;for(i = 1; i <= xlen; i++){for(j = 1; j < ylen; j++){cout << c[i][j] << " ";}cout << endl;}*/return c[xlen][ylen];}void Display_Lcs(int i, int j, string x, int b[][Y+1],int current_Len){if (i ==0 || j==0){return;}if(b[i][j]== 1){current_Len--;result[current_Len]=x[i- 1];Display_Lcs(i-1, j-1, x, b, current_Len);}else{if(b[i][j] == 2){Display_Lcs(i-1, j, x, b, current_Len);}else{if(b[i][j]==3){Display_Lcs(i, j-1, x, b, current_Len);}else{Display_Lcs(i-1,j,x,b, current_Len);}}}}int main(int argc, char* argv[]){string x;string y;cin>>x>>y;int xlen = x.length();int ylen = y.length();//int b[X + 1][Y + 1];int lcs_max_len = Lcs_Length( x, y, b, xlen,ylen );//cout << lcs_max_len << endl;Display_Lcs( xlen, ylen, x, b, lcs_max_len );//打印结果如下所示for(int i = 0; i < lcs_max_len; i++){cout << result[i];}cout << endl;return 0;}