最长公共子序列

例题AC897

#include <iostream>

using namespace std;

const int N = 1010;

int n, m;
char a[N], b[N];
int f[N][N];

int main()
{
    cin >> n >> m >> a + 1 >> b + 1;

    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;
}