Longest Common Subsequent

    1#include <bits/stdc++.h>
    2 
    3using namespace std;
    4 
    5int main(){
    6    ios::sync_with_stdio(0);
    7    cin.tie(0);
    8    int n, m;
    9    cin >> n >> m;
    10    vector<int> a(n), b(m);
    11    for(int i = 0; i < n; i++) cin >> a[i];
    12    for(int i = 0; i < m; i++) cin >> b[i];
    13    vector<vector<int>> dp(a.size() + 1, vector<int>(b.size() + 1));
    14    for(int i = 1; i <= a.size(); i++){
    15        for(int j = 1; j <= b.size(); j++){
    16            if(a[i - 1] == b[j - 1]){
    17                dp[i][j] = dp[i - 1][j - 1] + 1;
    18            } else{
    19                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
    20            }
    21        }
    22    }
    23    cout << dp[n][m] << '\n';
    24    return 0;
    25}