51Nod 1294 修改数组

 1 //2018-07-16 17:15:29
 2 #include <iostream>
 3 #include <cstdio>
 4 #include <algorithm>
 5 using namespace std;
 6 
 7 const int N = 1000005;
 8 
 9 int n;
10 int a[N], d[N], b[N], ans;
11 
12 int main(){
13     scanf("%d", &n);
14     int head = 0;
15     for(int i=1; i<=n; i++){
16         scanf("%d", &b[i]);
17         if(b[i]==0 && i==1) a[++head] = b[i]; //偷懒的地方 
18         if(b[i]-i >= 0) a[++head] = b[i]-i;
19         else ans++;
20     }
21     d[1] = a[1];
22     int len = 1;
23     for(int i=2; i<=head; i++){
24         if(a[i] >= d[len]) d[++len] = a[i];
25         else{
26             int j = upper_bound(d+1, d+len+1, a[i])-d;
27             d[j] = a[i]; 
28         }
29     }
30     printf("%d\n", head-len+ans);
31     
32     return 0;
33 }