莫名CE

#include<bits/stdc++.h>
using namespace std;

int f[45000][45000],len1,len2;
string x,y; 

int main()
{
	cin>>x>>y;
	len1=x.size();
	len2=y.size();
	memset(f,0,sizeof(f));
	for (int i=1;i<=len1;i++)
	{
		for (int j=1;j<=len2;j++)
		{
			if (x[i-1]==y[j-1])
	          f[i][j]=f[i-1][j-1]+1;
	    	else
	      	  f[i][j]=max(f[i-1][j],f[i][j-1]);
		}
	}
	cout<<f[len1][len2]<<endl;
	return 0;
}