CodeForces - 1007A (the double pointer Thinking +)

The meaning of problems

https://vjudge.net/problem/CodeForces-1007A

Rearrangement of a sequence, such that the new position of the maximum number than the number corresponding to a large number of the original.

Thinking

 For chestnuts, such as 122,333,345, then for a number, certainly bigger than he used to cover his smallest to the larger number have more chance to be covered behind this. 1 with the cover 2 such as, but not with a cover 5, because then 4 will not be covered. Consider scrambled, such as 213533432, the same, with a cover 2, a cover 3 2, and in fact no different ordered sequence, we take a direct sequence, double pointer traversal can be.

Code

#include<bits/stdc++.h>
using namespace std;
#define inf 0x3f3f3f3f
#define ll long long
const int N=200005;
const int mod=1e9+7;
const double eps=1e-8;
const double PI = acos(-1.0);
#define lowbit(x) (x&(-x))
int a[N];
int main()
{
    std::ios::sync_with_stdio(false);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i];
    sort(a+1,a+1+n);
    int i=1,j=1;
    for(;i<=n;i++)
    {
        if(a[i]>a[j])
        {
            j++;
        }
    }
    cout<<j-1<<endl;
    return 0;
}