1 #include<cstdio>
2 #include<cstring>
3 #include<algorithm>
4 using namespace std;
5 const int N = 50001;
6 int a[N];
7 int b[N];
8 int Search(int num, int low, int high){
9 int mid;
10 while(low <= high){
11 mid = (low + high)/2;
12 if(num >= b[mid]) low = mid + 1;
13 else high = mid - 1;
14 }
15 return low;
16 }
17 int DP(int n){
18 int i, len, pos;
19 b[1] = a[1];
20 len = 1;
21 for(i = 2; i <= n; i++){
22 if(a[i] >= b[len])
23 b[++len] = a[i];
24 else{
25 pos = Search(a[i],1,len);
26 //在b[]数组中找出第一个比a[i]大的位置并且让a[i]替代这个位置
27 b[pos] = a[i];
28 }
29 }
30 return len;
31 }
32 int main(){
33 int n, i, j;
34 scanf("%d", &n);
35 for(i = 1; i <= n; ++i)
36 scanf("%d", &a[i]);
37 int len = DP(n);
38 printf("%d\n", len);
39 return 0;
40 }
