HDU 1841 Find the Shortest Common Superstring----KMP

 

题意：给两个字符串，问包含这两个字符串的最小的字符串的长度

kmp返回匹配串长度

#include "iostream"
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
#define N 1000005
char  s[N],t[N];
int next1[N];
void get_next(char b[])
{
     next1[0]=-1;
     int i=0;
     int j=-1;
     int str=strlen(b);
     while(i<str-1)
     {
          if(j==-1||b[i]==b[j])
               next1[++i]=++j;
          else
               j=next1[j];
     }
}
int kmp(char a[],char b[],int stra,int strb)
{
     int i=0;
     int j=-1;
     get_next(b);///b为模式串
     while(i<stra&&j<strb)
     {
          if(j==-1||a[i]==b[j])
               i++,j++;
          else
               j=next1[j];
     }
     return j;
}
int main()
{
     int i,j,n,ans,cnt,ls,lt;
     scanf("%d",&n);
     while(n--)
     {
          scanf("%s%s",s,t);
          ls=strlen(s);
          lt=strlen(t);
          ans=kmp(s,t,ls,lt);
          cnt=kmp(t,s,lt,ls);
          printf("%d\n",ls+lt-max(ans,cnt));

     }
     return 0;
}