Codeforces Round #136 (Div. 2)

A. Little Elephant and Function

#include<cstdio>
#include <iostream>
using namespace std;
int main()
{
    int n,i;
    while(~scanf("%d",&n))
    {
        if(n==1) cout<<1<<endl;
        else
        {
            cout<<n<<" ";
            for(i=1;i<n-1;i++)
                cout<<i<<" ";
            cout<<n-1<<endl;
        }
    }
    return 0;
}

B. Little Elephant and Numbers

#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int n;
int f(int D)
{
    int t,d;
    while(D>0)
    {
        d=D%10;
        t=n;
        while(t>0)
    {
        if(t%10==d) return 1;
        t=t/10;
    }
        D=D/10;
    }
    return 0;
}
int main()
{
    int ans,i;
    while(~scanf("%d",&n))
    {
        if(n==1) cout<<1<<endl;
        else
        {for(i=1,ans=0;i*i<=n;i++)
        {
            if(n%i==0)
                {
                    if(f(i)==1)
                    ans++;
                    if(f(n/i)==1&&i!=n/i)
                    ans++;
                }
        }
        cout<<ans<<endl;}
    }
    return 0;
}

C. Little Elephant and Problem

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;

int main()
{
    int a[100005],b[100005];
    int n,i,ans;
    while(~scanf("%d",&n))
    {
        for(i=0;i<n;i++)
            {cin>>a[i];b[i]=a[i];}
        sort(a,a+n);
        for(i=0,ans=0;i<n;i++)
        {
            if(a[i]!=b[i]) ans++;
        }
        if(ans<=2) cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
    }
    return 0;
}