cf 10D lcis 最长上升子序列+输出路径

用个数组记录下路径然后dfs 输出就可以了

#include <stdio.h>
#include <string.h>
#include <algorithm>
#pragma warning (disable : 4996)
using namespace std;

const int Max = 505;
int dp[Max][Max], pre[Max][Max];
int a[Max], b[Max];
int m, n;

void dfs(int x)
{
if (pre
[x] == -1)
{
printf("%d", b[x]);
return;
}
dfs(pre
[x]);
printf(" %d", b[x]);
}

int main()
{
while (~scanf("%d", &n))
{
for (int i = 1; i <= n; i++)
scanf("%d", &a[i]);
scanf("%d", &m);
for (int i = 1; i <= m; i++)
scanf("%d", &b[i]);
memset(dp, 0, sizeof(dp));
memset(pre, -1, sizeof(pre));
for (int i = 1; i <= n; i++)
{
int pos = -1, maxn = 0;
for (int j = 1; j <= m; j++)
{
dp[i][j] = dp[i - 1][j];
pre[i][j] = pre[i - 1][j];
if (a[i] == b[j] && dp[i][j] < maxn + 1)
{
dp[i][j] = maxn + 1;
pre[i][j] = pos;
}
if (a[i] > b[j] && dp[i - 1][j] > maxn)
{
maxn = dp[i][j];
pos = j;
}
}
}
int ans = 1;
for (int i = 1; i <= m; i++)
{
if (dp
[ans] < dp
[i])
ans = i;
}
printf("%d\n", dp
[ans]);
if (dp
[ans])dfs(ans);
printf("\n");
}
return 0;
}