UVA 1625 Color Length

http://blog.csdn.net/sdfzyhx/article/details/51675691

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
const int maxn=5000+5;

int d[maxn][maxn],cnt[maxn][maxn],bg1[30],bg2[30],ed1[30],ed2[30];
int N[4],L[4];
void init()
{
memset(bg1,0,sizeof(bg1));
memset(bg2,0,sizeof(bg2));
memset(ed1,0,sizeof(ed1));
memset(ed2,0,sizeof(ed2));
}
int main()
{
int n;
cin>>n;
char s1[maxn],s2[maxn];
while(n--)
{
scanf("%s%s",s1+1,s2+1);

s1[0]=strlen(s1+1)+1;
s2[0]=strlen(s2+1)+1;

init();

for(int i=1;i<max(s1[0],s2[0]);i++)
{
if(i<s1[0]&&!bg1[s1[i]-'A']) bg1[s1[i]-'A']=i;
if(i<s2[0]&&!bg2[s2[i]-'A']) bg2[s2[i]-'A']=i;
}
for(int i=max(s2[0],s1[0]);i>=1;i--)
{
if(i<s1[0]&&!ed1[s1[i]-'A']) ed1[s1[i]-'A']=i;
if(i<s2[0]&&!ed2[s2[i]-'A']) ed2[s2[i]-'A']=i;
}

for(int i=0;i<s1[0];i++)
for(int j=0;j<s2[0];j++)
{
if(i) cnt[i][j]=cnt[i-1][j]+(bg1[s1[i]-'A']==i&&(bg2[s1[i]-'A']>j||bg2[s1[i]-'A']==0))
-(ed1[s1[i]-'A']==i&&(ed2[s1[i]-'A']<=j||ed2[s1[i]-'A']==0));

else if(j) cnt[i][j]=cnt[i][j-1]+(bg2[s2[j]-'A']==j&&(bg1[s2[j]-'A']>i||bg1[s2[j]-'A']==0))
-(ed2[s2[j]-'A']==j&&(ed1[s2[j]-'A']<=i||ed1[s2[j]-'A']==0));
}

for(int i=0;i<s1[0];i++)
for(int j=0;j<s2[0];j++)
{
if(!i&&!j) continue;
d[i][j]=(1<<30);
if(i) d[i][j]=min(d[i][j],d[i-1][j]+cnt[i-1][j]);
if(j) d[i][j]=min(d[i][j],d[i][j-1]+cnt[i][j-1]);
}

cout<<d[s1[0]-1][s2[0]-1]<<endl;
}
}