DP--最长上升子序列

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 100;
int a[maxn], d[maxn], c[maxn], n;

int dp(int i)
{
int ans = 0;
for(int j=i+1; j<=n; j++) {
if(a[i] < a[j]) ans = max(ans, dp(j) + 1);
}
return ans;
}

int main()
{
while(~scanf("%d", &n)) {
for(int i=1; i<=n; i++) {
scanf("%d", &a[i]);
d[i] = 1; c[i] = 0;
}

for(int i=n-1; i>0; i--) {
int mx = 0, p = 0;
for(int j=i+1; j<=n; j++) {
if(a[i]<a[j] && d[j]>mx) {
mx = d[j];
p = j;
}
}
if(p) {
d[i] = d[p] + 1;
c[i] = p;
}
}
int mx = 0, p = 0;
for(int i=1; i<=n; i++) if(d[i] > mx) {
mx = d[i]; p = i;
}
printf("%d\n", mx);
while(p) {
printf("%d ", a[p]);
p = c[p];
}
printf("\n%d\n", dp(0));
}
return 0;
}