lcs nlogn 算法

来源：互联网发布：如何下载excel2007软件编辑：程序博客网时间：2024/06/03 21:13

#include <map>#include <queue>#include <cmath>#include <cstdio>#include <cstring>#include <stdlib.h>#include <iostream>#include <algorithm>#define maxn 1005using namespace std;int a[maxn],dp[maxn];vector<int>location[26];char s1[maxn],s2[maxn];void init(){    for(int i=0;i<=maxn;++i)        a[i]=dp[i]=0;}void LCS(){    init();    int i,j,k,w,ans,l,r,mid;    int lena=strlen(s1),lenb=strlen(s2);    for(i=0;i<26;i++)location[i].clear();    for(i=lenb-1;i>=0;--i)location[s2[i]-'a'].push_back(i);    for(i=0,k=0;s1[i];i++)        for(j=0;j<location[w=s1[i]-'a'].size();++j,++k)            a[k]=location[w][j];    dp[1]=a[0];    dp[0]=-1;    for(i=ans=1;i<k;++i){        l=0;r=ans;        while(l<=r){            mid=(l+r)>>1;            if(dp[mid]>=a[i])r=mid-1;            else l=mid+1;        }        if(r==ans)            ans++,dp[r+1]=a[i];        else if(dp[r+1]>a[i])dp[r+1]=a[i];    }    cout<<ans<<'\12';}int main(){    while(scanf("%s%s",s1,s2)!=EOF)LCS();    return 0;}

0 0