最长公共子序列

 1 #include<iostream>
 2 using namespace std;
 3 
 4 int n,a[100001],b[100001],f[1001][1001];
 5 
 6 int main() {
 7     cin >> n;
 8     for(int i = 1;i <= n; i++) 
 9         cin >> a[i] >> b[i];
10     for(int i = 1;i <= n; i++)
11         for(int x = 1;x <= n; x++)
12             if(a[i-1] == b[i-1])
13                 f[i][x] = max(f[i-1][x-1] + 1, f[i][x]);
14             else
15                 f[i][x] = max(f[i-1][x], f[i][x-1]);
16     cout << f[n][n] <<endl;
17                         
18         
19         
20         
21     return 0;
22 }