POJ 2250 Compromise (线性dp LCS ＋递归路径)

#include <iostream>
#include <cstring>
#include <string>
#include <algorithm>
using namespace std;
int dp[105][105];
int path[105][105];
string ans[105];
string a[105], b[105];
int cnta, cntb, cnt, num;

void init()
{
    cnt = cnta = cntb = num = 0;
    memset(dp, 0, sizeof(dp));
    memset(path, 0, sizeof(path));
}

void Get(int i, int j)
{
    if(!i || !j)
        return;
    if(path[i][j] == 0)
    {
        Get(i - 1, j - 1);
        ans[num ++] = a[i - 1];
    }
    else if(path[i][j] == 1)
        Get(i - 1, j);
    else
        Get(i, j - 1);
}

int main()
{
    string s;
    init();
    while(cin >> s)
    {
        if(s[0] == '#')
            cnt ++;
        if(cnt == 0 && s[0] != '#')
            a[cnta ++] = s;
        if(cnt == 1 && s[0] != '#')
            b[cntb ++] = s;
        if(cnt == 2)
        {
            for(int i = 1; i <= cnta; i++)
            {
                for(int j = 1; j <= cntb; j++)
                {
                    if(a[i - 1] == b[j - 1])
                    {
                        dp[i][j] = dp[i - 1][j - 1] + 1;
                        path[i][j] = 0;
                    }
                    else if(dp[i - 1][j] > dp[i][j - 1])
                    {
                        dp[i][j] = dp[i - 1][j];
                        path[i][j] = 1;
                    }
                    else 
                    {
                        dp[i][j] = dp[i][j - 1];
                        path[i][j] = -1;
                    }
                }
            }
            Get(cnta, cntb);
            for(int i = 0; i < num - 1; i++)
                cout << ans[i] << " ";
            cout << ans[num - 1] << endl;
            init();
        }
    }
}