AcWing_897 最长公共子序列(线性DP)

#include <bits/stdc++.h>
using namespace std;
int n, m;
const int N = 1010, M = 1010;
char a[N], b[M];
int f[N][M];
int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; i++) cin >> a[i];
    for(int i = 1; i <= m; i++) cin >> b[i];
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            f[i][j] = max(f[i - 1][j], f[i][j - 1]);
            if(a[i] == b[j]) f[i][j] = max(f[i][j], f[i - 1][j - 1] + 1);
        }
    }
    cout << f[n][m] << endl;
    return 0;
}