USACO : Prime Palindromes

0

Problem Link : http://train.usaco.org/usacoprob2?a=tffkkLavmsp&S=pprime


/*
PROG: pprime
LANG: C++
*/

#include <bits/stdc++.h>

#define pii             pair <int,int>
#define sc              scanf
#define pf              printf
#define Pi              2*acos(0.0)
#define ms(a,b)         memset(a, b, sizeof(a))
#define pb(a)           push_back(a)
#define MP              make_pair
#define db              double
#define ll              long long
#define EPS             10E-10
#define ff              first
#define ss              second
#define sqr(x)          (x)*(x)
#define D(x)            cout<<#x " = "<<(x)<<endl
#define VI              vector <int>
#define DBG             pf("Hi\n")
#define MOD             100007
#define MAX             10000
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define SZ(a)           (int)a.size()
#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 loop(i,n)       for(int i=0;i<n;i++)
#define REP(i,a,b)      for(int i=a;i<=b;i++)
#define TEST_CASE(t)    for(int z=1;z<=t;z++)
#define PRINT_CASE      printf("Case %d: ",z)
#define all(a)          a.begin(),a.end()
#define intlim          2147483648
#define inf             1000000
#define ull             unsigned long long

using namespace std;


/*----------------------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
/*------------------------------------------------*/

/*-----------------------Bitmask------------------*/
//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/


bool isPrime(ll n)
{
    if(!(n & 1))
        return false;
    else
    {
        int root= sqrt(n);
        for(int i=3; i<=root+1; i+=2)
            if(n%i==0) return false;
    }
    return true;
}


vector<ll>v;

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

    ll a,b;
    cin>>a>>b;

    bool test=1;

    for(int i=0; i<10 && test; i++)
        for(int j=0; j<10 && test; j++)
            for(int k=0; k<10 && test; k++)
                for(int l=0; l<10 && test; l++)
                {
                    ll palin=10*l+l;
                    if(k)
                    {
                        palin=1000*k+k+palin*10;
                    }
                    if(j)
                    {
                        if(k==0) palin=100000*j+j+palin*100;
                        else
                            palin=100000*j+j+palin*10;
                    }
                    if(i)
                    {
                        if(k==0 && j==0) palin=10000000*i+i+palin*1000;
                        else if(k!=0 && j==0) palin=10000000*i+i+palin*100;
                        else
                            palin=10000000*i+i+palin*10;
                    }
                    if(palin>b)
                    {
                        test=0;
                        break;
                    }
                    if(palin>=a && isPrime(palin))
                        v.pb(palin);
                }

    test=1;

    for(int i=0; i<10 && test; i++)
        for(int j=0; j<10 && test; j++)
            for(int k=0; k<10 && test; k++)
                for(int l=0; l<10 && test; l++)
                {
                    ll palin=l;
                    if(k)
                    {
                        palin=100*k+k+palin*10;
                    }
                    if(j)
                    {
                        if(k==0) palin=10000*j+j+palin*100;
                        else
                            palin=10000*j+j+palin*10;
                    }
                    if(i)
                    {
                        if(k==0 && j==0) palin=1000000*i+i+palin*1000;
                        else if(k!=0 && j==0) palin=1000000*i+i+palin*100;
                        else
                            palin=1000000*i+i+palin*10;
                    }
                    if(palin>b)
                    {
                        test=0;
                        break;
                    }
                    if(palin>=a && isPrime(palin))
                        v.pb(palin);
                }
    sort(all(v));
    loop(i,SZ(v)) cout<<v[i]<<endl;
    return 0;
}


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USACO : Arithmetic Progressions

0

Problem Link : http://train.usaco.org/usacoprob2?a=tffkkLavmsp&S=ariprog


/*
  PROG: ariprog
  LANG: C++
 */

#include <bits/stdc++.h>

#define pii             pair <int,int>
#define sc              scanf
#define pf              printf
#define Pi              2*acos(0.0)
#define ms(a,b)         memset(a, b, sizeof(a))
#define pb(a)           push_back(a)
#define MP              make_pair
#define db              double
#define ll              long long
#define EPS             10E-10
#define ff              first
#define ss              second
#define sqr(x)          (x)*(x)
#define D(x)            cout<<#x " = "<<(x)<<endl
#define VI              vector <int>
#define DBG             pf("Hi\n")
#define MOD             100007
#define MAX             10000
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define SZ(a)           (int)a.size()
#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 loop(i,n)       for(int i=0;i<n;i++)
#define REP(i,a,b)      for(int i=a;i<=b;i++)
#define TEST_CASE(t)    for(int z=1;z<=t;z++)
#define PRINT_CASE      printf("Case %d: ",z)
#define all(a)          a.begin(),a.end()
#define intlim          2147483648
#define inf             1000000
#define ull             unsigned long long

using namespace std;


/*----------------------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
/*------------------------------------------------*/

/*-----------------------Bitmask------------------*/
//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int n,m;

bool present[300000];

int main()
{
    freopen("ariprog.in","r",stdin);
    freopen("ariprog.out","w",stdout);
    int maxx=INT_MIN;
    cin>>n>>m;
    for(int i=0; i<=m; i++) for(int j=0; j<=m; j++) present[i*i+j*j]=1,maxx=max(maxx,i*i+j*j);
    vector<int>v;
    REP(i,0,maxx) if(present[i]) v.pb(i);

    vector<pii>ans;

    int l=SZ(v);

    for(int i=0; i<l; i++)
        for(int j=i+1; j<l; j++)
        {
            int dis=v[j]-v[i];
            int k;
            int sum=v[i]+dis;
            for(k=0; k<n-2; k++)
            {
                sum+=dis;
                if(!present[sum] || sum>2*m*m)
                {
                    break;
                }
            }
            if(k==n-2)
                ans.pb(MP(dis,v[i]));
        }
    sort(all(ans));
    if(SZ(ans))
        loop(i,SZ(ans)) cout<<ans[i].ss<<" "<<ans[i].ff<<endl;
    else
        cout<<"NONE"<<endl;
    return 0;
}