最长公共子序列的代码实现

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int A[100];
 4 int B[100];
 5 
 6 //int B[]={2,3,5,6,9,8,4};
 7 int d[100][100]={0};
 8 int dp(int i, int j,vector<int> &vs){
 9     int &ans = d[i][j];
10     if(ans > 0)return ans;
11     if(i>0&&j>0){
12         if(A[i] == B[j]){
13             ans = dp(i-1,j-1)+1;
14         } 
15         else ans = max(dp(i-1,j),dp(i,j-1));
16     }
17     else{
18         ans  = 0;
19     }
20     return ans;
21 }
22 int LCS(int n1, int n2){
23     for(int i = 0; i <= n1; i++)d[i][0] = 0;
24     for(int i = 0; i <= n2; i++)d[0][i] = 0;    
25     for(int i = 1; i<= n1; i++){
26         for(int j = 1; j<= n2; j++){
27             if(A[i]==B[j]){
28                 d[i][j] = d[i-1][j-1]+1;
29             }
30             else d[i][j] = max(d[i-1][j], d[i][j-1]);
31         }
32     }
33     return d[n1][n2];
34 }
35 int main(){
36     int n1,n2 ;
37     cin >> n1;
38     for(int i = 1;i <= n1; i++) cin >> A[i];
39     cin >> n2;
40     for(int i = 1;i <= n2; i++) cin >> B[i];
41     memset(d,-1,sizeof(d));
42     d[0][0] = 0;
43     vector<int> vs;
44     cout << dp(n1,n2,vs) << endl;
45     cout << LCS(n1 ,n2) << endl;
46     //cout << dp(5,6) << endl;
47 
48     return 0;
49 }