UVa – 294 – Divisors

#include <bits/stdc++.h>

#define pf                  printf
#define sf(a)               scanf("%d",&a)
#define sfl(a)              scanf("%lld",&a)
#define sff(a,b)            scanf("%d %d",&a,&b)
#define sffl(a,b)           scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)         scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)        scanf("%lld %lld %lld",&a,&b,&c)
#define sffff(a,b,c,d)      scanf("%d %d %d %d",&a,&b,&c,&d)
#define sffffl(a,b,c,d)     scanf("%lld %lld %lld %lld",&a,&b,&c,&d)
#define sfffff(a,b,c,d,e)   scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)
#define sfffffl(a,b,c,d,e)  scanf("%lld %lld %lld %lld %lld",&a,&b,&c,&d,&e)
#define ms(a,b)             memset(a,b,sizeof(a))
#define pb(a)               push_back(a)
#define pbp(a,b)            push_back({a,b})
#define db                  double
#define ft                  float
#define ll                  long long
#define ull                 unsigned long long
#define ff                  first
#define ss                  second
#define sz(x)               x.size()
#define qu                  queue
#define pqu                 priority_queue
#define vc                  vector
#define vi                  vector<int>
#define vll                 vector<long long>
#define pii                 pair<int,int>
#define pis                 pair<int,string>
#define psi                 pair<string,int>
#define all(x)              x.begin(),x.end()
#define CIN                 ios_base::sync_with_stdio(0); cin.tie(0)
#define max3(a, b, c)       max(a, b) > max(b, c) ? max(a, b) : max(b, c)
#define min3(a, b, c)       min(a, b) < min(b, c) ? min(a, b) : min(b, c)
#define loop0(i,n)          for(int i=0;i<n;i++)
#define loop1(i,n)          for(int i=1;i<=n;i++)
#define loopab(i,a,b)        for(int i=a;i<=b;i++)
#define stlloop(x)          for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)           __gcd(a, b)
#define lcm(a, b)           ((a)*((b)/gcd(a,b)))
#define case1(z)            cout<<"Case "<<z<<": "
#define case2(z)            printf("Case %d: ",z)
#define PI                  3.14159265358979323846264338328
#define valid(tx,ty)        tx>=0 && tx<r && ty>=0 && ty<c
#define intlim              2147483648
#define MAX                 100000
#define inf                 10000000

/*------------------------------Graph Moves----------------------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*---------------------------------------------------------------------*/

using namespace std;

bool p[MAX+2];
vector<int>prime;
vector<ll> v;

void sieve()
{
    p[0]=p[1]=1;
    int root=sqrt(MAX);
    for(int i=2; i<=root; i++)
    {
        if(p[i]==0)
        {
            for(int j=i*i; j<=MAX; j+=i)
            {
                p[j]=1;
                if(i%2==1) j+=i;
            }
        }
    }
    for(int i=2;i<=MAX;i++)
    {
        if(p[i]==0) prime.push_back(i);
    }
}

int divisor_count(int n)
{
    int divisor=1;
    int k=n;
    int root=sqrt(n);
    for(int i=0;prime[i]<=root;i++)
    {
        if(k%prime[i]==0)
        {
            int c=1;
            while(k%prime[i]==0)
            {
                k/=prime[i];
                c++;
            }
            root=sqrt(k);
            divisor*=c;
        }
    }
    if(k>1)
    {
        divisor*=2;
    }
    return divisor;
}


int main()
{
    //CIN;
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
    sieve();
    int t;
    sf(t);
    loop1(z,t)
    {
        ll a,b,ans=0;
        sffl(a,b);
        ll x,num;
        loopab(i,a,b)
        {
            x=divisor_count(i);
            if(x>ans)
            {
                ans=x;
                num=i;
            }
        }
        pf("Between %lld and %lld, %lld has a maximum of %lld divisors.\n",a,b,num,ans);
    }
    return 0;
}

UVa – 10299 – Relatives

#include <bits/stdc++.h>
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)

using namespace std;

bool p[1000000];

vector<int>prime;


void sieve(long long n)
{
    p[0]=p[1]=1;

    for(long long i=2; i<n;)
    {
        prime.push_back(i);
        for(long long j=i*i; j<n; j+=i)
            p[j]=1;
        for(++i;;i++)
        {
            if(!p[i]) break;
        }
    }
}

long long phi(long long n)
{
    long long ans=n;
    for(long long i=0; prime[i]<=sqrt(n); i++)
    {
        if(n%prime[i]==0)
        {
            while(n%prime[i]==0)
            {
                n/=prime[i];
            }
            ans-=ans/prime[i];
        }
    }

    if(n>1)
    {

        ans-=ans/n;
    }
    return ans;
}

int main()
{
    CIN;
    long long n;
    sieve(1000000);
    while(cin>>n)
    {
        if(n==1)
        {
            cout<<0<<endl;
            continue;
        }
        if(n==0) break;

        cout<<phi(n)<<endl;
    }

}

UVa – 10179 – Irreducible Basic Fractions

#include <bits/stdc++.h>
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)

using namespace std;

bool p[1000000];

vector<int>prime;


void sieve(long long n)
{
    p[0]=p[1]=1;

    for(long long i=2; i<n;)
    {
        prime.push_back(i);
        for(long long j=i*i; j<n; j+=i)
            p[j]=1;
        for(++i;;i++)
        {
            if(!p[i]) break;
        }
    }
}

long long phi(long long n)
{
    long long ans=n;
    for(long long i=0; prime[i]<=sqrt(n); i++)
    {
        if(n%prime[i]==0)
        {
            while(n%prime[i]==0)
            {
                n/=prime[i];
            }
            ans-=ans/prime[i];
        }
    }

    if(n>1)
    {
        ans-=ans/n;
    }
    return ans;
}

int main()
{
    //freopen("in.txt","r",stdin);
    CIN;
    long long n;
    sieve(1000000);
    while(cin>>n)
    {
        if(n==1)
        {
            cout<<1<<endl;
            continue;
        }
        if(n==0) break;

        cout<<phi(n)<<endl;
    }

}

UVa – 10127 – Ones

#include <bits/stdc++.h>

#define sf              scanf
#define pf              printf
#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define sz(x)           x.size()
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(tx,ty)    tx>=0 && tx<r && ty>=0 && ty<c
#define MAX             2000
#define inf             10000000

/*------------------------------Graph Moves----------------------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*---------------------------------------------------------------------*/

using namespace std;

int m;
int bigmod(int a,int p)
{
    if(p==0) return 1;
    if(p%2==0)
    {
        return ((bigmod(a,p/2)%m)*(bigmod(a,p/2)%m))%m;
    }
    else
        return ((a%m)*(bigmod(a,p-1)%m))%m;
}

int main()
{
    CIN;
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);

    while(cin>>m)
    {
        int x=1,c=1;
        while(x!=0)
        {
            x=(x*10)+1;
            c++;
            x=bigmod(x,1);
        }
        cout<<c<<endl;
    }
    return 0;
}

UVa – 374 – Bigmod

//#include <bits/stdc++.h>
//
//#define ms(a,b)         memset(a,b,sizeof(a))
//#define pb(a)           push_back(a)
//#define db              double
//#define ft              float
//#define ll              long long
//#define ull             unsigned long long
//#define ff              first
//#define ss              second
//#define sz(x)           x.size()
//#define qu              queue
//#define pqu             priority_queue
//#define vc              vector
//#define vi              vector<int>
//#define vll             vector<long long>
//#define pii             pair<int,int>
//#define pis             pair<int,string>
//#define psi             pair<string,int>
//#define all(x)          x.begin(),x.end()
//#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
//#define loop0(i,n)      for(int i=0;i<n;i++)
//#define loop1(i,n)      for(int i=1;i<=n;i++)
//#define stlloop(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
//#define gcd(a, b)       __gcd(a, b)
//#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
//#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
//#define case(z)         cout<<"Case "<<z<<": "
//#define PI              3.14159265358979323846264338328
//#define valid(tx,ty)    tx>=0 && tx<r && ty>=0 && ty<c
//#define MAX             2000
//#define inf             10000000
//
///*----------------------Graph Moves----------------*/
////const int fx[]={+1,-1,+0,+0};
////const int fy[]={+0,+0,+1,-1};
////const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
////const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
////const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
////const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
///*------------------------------------------------*/
//
//using namespace std;
//
//ll big_mod(ll n, ll pow, ll mod)
//{
//    if(pow==0) return 1;
//    if(pow==1) return n;
//
//    ll ret=0;
//
//    if(pow%2==0)
//    {
//        ret=big_mod(n,pow/2,mod)%mod;
//        return (ret*ret)%mod;
//    }
//    else
//        return ((n%mod)*(big_mod(n,pow-1,mod))%mod)%mod;
//
//}
//
//int main()
//{
//    CIN;
//    //freopen("out.txt","w",stdout);
//    ll a,b,c;
//    cin>>a>>b>>c;
//    cout<<big_mod(a,b,c)<<endl;
////    ll d=1;
////    for(int i=0;i<b;i++)
////    {
////        d*=a;
////        d%=c;
////    }
////    cout<<d<<endl;
//
//    return 0;
//}




#include <bits/stdc++.h>

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define sz(x)           x.size()
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(tx,ty)    tx>=0 && tx<r && ty>=0 && ty<c
#define MAX             2000
#define inf             10000000

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

using namespace std;

ll a,b,m;
ll bigmod(ll n,ll p)
{
    if(p==0) return 1;
    if(p%2==0)
    {
        return ((bigmod(n,p/2)%m)*(bigmod(n,p/2)%m))%m;
    }
    else
        return ((n%m)*(bigmod(n,p-1)%m))%m;
}

int main()
{
    CIN;
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);

    while(cin>>a>>b>>m)
    {
        cout<<bigmod(a,b)<<endl;
    }
    return 0;
}