C. Day at the Beach

codeforces 599c

C. Day at the Beach

One day Squidward, Spongebob and Patrick decided to go to the beach. Unfortunately, the weather was bad, so the friends were unable to ride waves. However, they decided to spent their time building sand castles.

At the end of the day there were n castles built by friends. Castles are numbered from 1 to n, and the height of the i-th castle is equal to hi. When friends were about to leave, Squidward noticed, that castles are not ordered by their height, and this looks ugly. Now friends are going to reorder the castles in a way to obtain that condition hi ≤ hi + 1 holds for all i from 1 to n - 1.

Squidward suggested the following process of sorting castles:

• Castles are split into blocks — groups of consecutive castles. Therefore the block from i to j will include castlesi, i + 1, ..., j. A block may consist of a single castle.
• The partitioning is chosen in such a way that every castle is a part of exactly one block.
• Each block is sorted independently from other blocks, that is the sequence hi, hi + 1, ..., hj becomes sorted.
• The partitioning should satisfy the condition that after each block is sorted, the sequence hi becomes sorted too. This may always be achieved by saying that the whole sequence is a single block.

Even Patrick understands that increasing the number of blocks in partitioning will ease the sorting process. Now friends ask you to count the maximum possible number of blocks in a partitioning that satisfies all the above requirements.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 100 000) — the number of castles Spongebob, Patrick and Squidward made from sand during the day.

The next line contains n integers hi (1 ≤ hi ≤ 109). The i-th of these integers corresponds to the height of the i-th castle.

Output

Print the maximum possible number of blocks in a valid partitioning.

Sample test(s)

input

3
1 2 3

output

3

input

4
2 1 3 2

output

2

Note

In the first sample the partitioning looks like that: [1][2][3].

In the second sample the partitioning is: [2, 1][3, 2】

题意：给出一组数据，要求你进行分块选择，如 2 1 3 2分成【2,1】，【3,2】，那么块内进行排序之后这些块拼接起来就是一个有序序列，要求分成尽可能多的块

思路：开始以为是寻求最长上升子序列的题，然而 1 3 5 1 3 6这组数据就是一个反例。。。。。

应该是逐个查看：以i为分界线，那么在i之前找一个最大数MAX，在i之后找一个最小数MIN，如果如果MAX小于等于MIN，那么答案就累加1，代表i这个数字可以分成一个独立的块（为什么？因为如果i之后存在一个比它小的数，那么它肯定不能成为前面的一个独立的块，同理，i之前如果有一个大于i的数大于i之后的最小数，那么i也不能成为独立的一个快，它必须存在于MAX到MIN之间）

 

 

#include <iostream>
#include <cstring>
#include <queue>
#define M(a) memset(a,0,sizeof(a))
using namespace std;
const int maxsize=1e5+10;
int a[maxsize];
int MIN[maxsize];
int main()
{
    int n;
    while(cin>>n)
    {
     for(int i=1;i<=n;i++) {cin>>a[i];}

     int mi=1e9+10;
     for(int i=n;i>=1;i--)
     {
         mi=min(mi,a[i]);
         MIN[i]=mi;
     }

     int ans=0;
     int maxx=a[1];
     for(int i=1;i<=n;i++)
     {
        maxx=max(maxx,a[i]);
        if(i==n) {ans++; continue;}
        int minx=MIN[i+1];
        if(maxx<=minx) ans++;
     }
     cout<<ans<<endl;
    }
    return 0;
}