【模板】最长不下降子序列

 1 //2018-07-16 17:42:40
 2 #include <iostream>
 3 #include <cstdio>
 4 using namespace std;
 5 
 6 const int N = 10000001;
 7 
 8 int n;
 9 int a[N], d[N];
10 
11 int main(){
12     scanf("%d", &n);
13     for(int i=i; i<=n; i++) scanf("%d", &a[i]);
14     
15     d[1] = a[1];
16     int len = 1;
17     for(int i=2; i<=n; i++){
18         if(a[i] >= d[len]) d[++len] = a[i];
19         else{
20             int j = upper_bound(d+1, d+len+1, a[i]) - d;
21             d[j] = a[i];
22         }
23     }
24     printf("%d\n", len);
25     
26     return 0;
27 }