COGS 445. [HAOI2010]最长公共子序列

#include<iostream>
#include<cstdio>
#include<cstring>
#define mod 100000000
#define maxn 5010
using namespace std;
int l1,l2,f[maxn][maxn],s[maxn][maxn];
char s1[maxn],s2[maxn];
int main()
{
    freopen("lcs.in","r",stdin);
    freopen("lcs.out","w",stdout);
    scanf("%s%s",s1+1,s2+1);
    l1=strlen(s1+1);l1--;
    l2=strlen(s2+1);l2--;
    for(int i=0;i<=l1;i++)s[i][0]=1;
    for(int i=1;i<=l2;i++)s[0][i]=1;
    for(int i=1;i<=l1;i++)
        for(int j=1;j<=l2;j++){
            if(s1[i]==s2[j]){
                f[i][j]=f[i-1][j-1]+1;
                s[i][j]=s[i-1][j-1];
            }
            else f[i][j]=max(f[i][j-1],f[i-1][j]);
            if(f[i][j]==f[i-1][j])s[i][j]+=s[i-1][j];
            if(f[i][j]==f[i][j-1])s[i][j]+=s[i][j-1];
            if(f[i][j]==f[i-1][j-1]&&s1[i]!=s2[j])
                s[i][j]-=s[i-1][j-1];
            s[i][j]%=mod;
        }
    printf("%d\n%d\n",f[l1][l2],s[l1][l2]);
    return 0;
}