A - Nastya and an Array
CodeForces - 992A
Nastya owns too many arrays now, so she wants to delete the least important of them. However, she discovered that this array is magic! Nastya now knows that the array has the following properties:
- In one second we can add an arbitrary (possibly negative) integer to all elements of the array that are not equal to zero.
- When all elements of the array become equal to zero, the array explodes.
Nastya is always busy, so she wants to explode the array as fast as possible. Compute the minimum time in which the array can be exploded.
Input
The first line contains a single integer n (1 ≤ n ≤ 105) — the size of the array.
The second line contains n integers a1, a2, ..., an ( - 105 ≤ ai ≤ 105) — the elements of the array.
Output
Print a single integer — the minimum number of seconds needed to make all elements of the array equal to zero.
Examples
Input
5
1 1 1 1 1
Output
1
Input
3
2 0 -1
Output
2
Input
4
5 -6 -5 1
Output
4
Note
In the first example you can add - 1 to all non-zero elements in one second and make them equal to zero.
In the second example you can add - 2 on the first second, then the array becomes equal to [0, 0, - 3]. On the second second you can add 3 to the third (the only non-zero) element.
//第一种代码
#include<bits/stdc++.h>
using namespace std;
int main()
{
vector <int> b;
int n,a,c,i;
cin>>n;
while(n--)
{
cin>>a;
b.push_back(a);
}
sort(b.begin(),b.end());
b.erase(unique(b.begin(),b.end()),b.end());
c=0;
for(i=0;i<b.size();i++)
{
if(b[i]!=0)
c++;
}
cout<<c;
return 0;
}
//第二种代码
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
int n,i,c,m;
int a[100100]={0};
cin>>n;
for(i=0;i<n;i++)
cin>>a[i];
sort(a,a+n);
c=0;
if(a[0]!=0)
c++;
for(i=1;i<n;i++)
{
if(a[i]!=a[i-1]&&a[i]!=0)
c++;
}
cout<<c;
return 0;
}
//第三种代码
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
int n,i,m,c;
int a[101000];
cin>>n;
for(i=0;i<n;i++)
{
cin>>a[i];
}
sort(a,a+n);//排序
m=unique(a,a+n)-a;//去重同时把去重后的长度赋值给m
for(i=0;i<m;i++)
{
if(a[i]==0)
{
m--;
break;
}
}
cout<<m;
return 0;
}