DP。还是LCS问题。

应该是有空格或者 Tab 。用scanf 就WA了。gets 就AC了。

#include<cstdio>
#include<cstring>
#include<string>
#include<queue>
#include<algorithm>
#include<map>
#include<stack>
#include<iostream>
#include<list>
#include<set>
#include<vector>
#include<cmath>

#define INF 0x7fffffff
#define eps 1e-8
#define LL long long
#define PI 3.141592654
#define CLR(a,b) memset(a,b,sizeof(a))
#define FOR(i,a,n) for(int i= a;i< n ;i++)
#define FOR0(i,a,b) for(int i=a;i>=b;i--)
#define pb push_back
#define mp make_pair
#define ft first
#define sd second
#define sf scanf
#define pf printf
#define acfun std::ios::sync_with_stdio(false)

#define SIZE 1000+1
using namespace std;
char a[SIZE],b[SIZE];
int dp[SIZE][SIZE];
int main()
{
    while(gets(a)!=NULL)
    {
        gets(b);
        CLR(dp,0);
        int la=strlen(a);
        int lb=strlen(b);
        FOR(i,0,la)
        FOR(j,0,lb)
        {
            if(a[i]==b[j])
                dp[i+1][j+1]=dp[i][j]+1;
            else
                dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j]);
        }
        pf("%d\n",dp[la][lb]);
    }
}

UVA 10405 Longest Common Subsequence