POJ 3356

都是最长公共子序列。。。。水题，前面的代码就没呢改，加了一个变量就过了，不解释

Source Code

Problem: 3356  User: XXX
Memory: 172K  Time: 16MS 
Language: C++  Result: Accepted 

Source Code 
#include <stdio.h>
#include <string.h>
int main()
{
      char str1[1005] ,str2[1005];
      int len1 ,len2 ,len ,i ,j ,dp[2][1005];
      while(scanf("%d %s %d %s" ,&len1 ,&str1 ,&len2 ,&str2) != EOF)
      {
             memset(dp ,0 ,sizeof(dp));
             for(i = 1 ;i <= len1 ;i++)
             {
                  for(j = 1 ;j <= len2 ;j++)
                  {
                      if(str1[i - 1] == str2[j - 1])
                          dp[i % 2][j] = dp[(i - 1) % 2][j - 1] + 1;
                      else
                          dp[i % 2][j] = dp[(i - 1) % 2][j] > dp[i % 2][j - 1] ? dp[(i - 1) % 2][j] : dp[i % 2][j - 1];
                  }
             }
             len = len1 > len2 ? len1 : len2;
             printf("%d\n",len - dp[len1 % 2][len2]);
      }
      return 0;
}