hdu1423LCIS zoj2432 必须掌握！

LCIS就是最长上升公共子序列，要结合LIS和LCS来求

LIS：f[j]=max(f[i])+1;

LCS:f[i,j]=max(f[i-1,j],f[i,j-1]或f[i-1,j-1]+1

那么对于LCIS，定义f[i][j]是以B[j]为结尾的最长公共上升子序列长度，

如果A[i]！=B[j]，那么f[i][j]=f[i-1][j]，

否则 f[i][j]=max(d[i-1][k])+1;1<=k<=j-1

最后扫描一次f[n][j],找到最大的

zoj2432需要用pre数组保存前驱pre[i][j]表示以b[j]结尾的上一个字符在b中的下标，即记录LCIS并输出

#include<iostream>
#include<cstdio>
#include<cstring>
#include<vector>
#include<string.h>
using namespace std;
const int maxn = 1000 + 5;
#define LL long long
int n, m;
LL a[maxn], b[maxn];
int f[maxn][maxn];
int pre[maxn][maxn];
 
int main()
{
    int T; cin >> T;
    while (T--) {
        scanf("%d", &n);
        for (int i = 1; i <= n; ++i) scanf("%lld", a + i);
        scanf("%d", &m);
        for (int i = 1; i <= m; ++i) scanf("%lld", b + i);
        memset(pre, -1, sizeof(pre));
        memset(f, 0, sizeof(f));
        for (int i = 1; i <= n; ++i) {
            int v = 0, k = 0;
            for (int j = 1; j <= m; ++j) {
        //        pre[i][j] = pre[i - 1][j];
                f[i][j] = f[i - 1][j];
                if (a[i] > b[j] && v < f[i - 1][j]) v = f[i - 1][j], k = j;
                if (a[i] == b[j] && v + 1>f[i][j]) f[i][j] = v + 1, pre[i][j] = k;
            }
        }
        int k = 1;
        for (int i = 1; i <= m; ++i)
        if (f[n][i]>f[n][k]) k = i;
        printf("%d
", f[n][k]);
        if (f[n][k] == 0) continue;
        int i = n;
        vector<int> ans;
        for (int i = n; i >= 1;--i) 
        if (pre[i][k] != -1) ans.push_back(a[i]), k = pre[i][k];
        printf("%d", ans.back());
        for (int i = ans.size() - 2; i >= 0; --i) printf(" %d", ans[i]);
        printf("
");
    }
}