OJ Board

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#include <iostream.h>
#include "math.h"

typedef struct 
{
	int prime;
	int num;
}Prime;

bool IfPrime (int n)
{
	int limit;

	if (n == 2)
		return true;
	if (n % 2 == 0)
		return false;

	limit = sqrt (n) + 1;

	for (int i = 3; i < limit; i = i + 2)
		if (n % i == 0)
			return false;
	return true;
}

int main ()
{
	int n, m;
	int i, j, temp;
	long long result;
	Prime p[6544];
	int pNum = 0;

	for (i = 0; i <= 65536; i++)
		if (IfPrime (i))
			p[pNum++].prime = i;

	while (cin>>n>>m && n||m)
	{
		result = 1;
		for (i = 1; i < 6544; i++)
			p[i].num = 0;

		for (i = 2; i <= n; i++)
		{
			temp = i;
		
			for (j = 1; temp != 1; j++)
			{
				while (temp % p[j].prime == 0)
				{
					p[j].num++;
					temp = temp / p[j].prime;
				}
			}			
		}

		for (i = 2; i <= m; i++)
		{
			temp = i;
		
			for (j = 1; temp != 1; j++)
			{
				while (temp % p[j].prime == 0)
				{
					p[j].num--;
					temp = temp / p[j].prime;
				}
			}			
		}

		for (i = 2; i <= n - m; i++)
		{
			temp = i;
		
			for (j = 1; temp != 1; j++)
			{
				while (temp % p[j].prime == 0)
				{
					p[j].num--;
					temp = temp / p[j].prime;
				}
			}			
		}

		for (i = 1; i < 26; i++)
		{
			for (j = 0; j < p[i].num; j++)
				result *= p[i].prime;
		}
		
		cout<<result<<endl;
	}
	return 0;
}

Code: Select all

110 6

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110 * 109 * 108 * 107 * 106 * 105
-------------------------------------------
        6 * 5 * 4 * 3 * 2 * 1

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#include <iostream>
#include <vector>

using namespace std;

int gcd (int u, int v)
{
    int t;
    while (u>0)
    {
          if (u<v) {t=u;u=v;v=t;}
          u=u-v;
    }
    return v;
}

int main ()
{
    long long double n,m,r,h;
    bool first=true;
    vector <int> n1,m1;
    while (cin>>n>>m)
    {
          if (n==0 && m==0) break;
          if (!first) cout<<endl; else first=false;
          r=1;
          n1.clear();
          m1.clear();
          for (int i=n-m+1;i<n+1;i++)
          {n1.push_back(i);}
          for (int i=2;i<m+1;i++)
          {m1.push_back(i);}
          for (int i=0;i<n1.size();i++)
          {
              for (int j=0;j<m1.size();j++)
              {
                  h=gcd(n1[i],m1[j]);
                  if (n1[i]>1 && m1[j]>1 && h>1)
                  {
                      n1[i]/=h;m1[j]/=h;
                  }
              }
          }
          for (int i=0;i<n1.size();i++) {r*=n1[i];}
          cout<<r<<endl;
    }
    return 0;
}

Code: Select all

#include<iostream>

using namespace std;

int main()
{
 int n,m,maior;
 double numerador,denominador, res;
 long long c;
 
 cin >> n >> m;
 
 while( n != 0 && m != 0)
 {
   numerador = denominador = res =1;
   c = 0;
   maior = max(m,n-m);
  
   for(numerador = n, denominador = n - maior; numerador > maior; numerador--,denominador--)
    {
      res = res * (numerador/denominador);
    }
    
    cout << n <<" things taken "<< m << " at a time is " << (long long)res << " exactly."<< endl;
    cin >> n >> m;
  
 }
 return 0;
}

Code: Select all

#include<iostream>
#include<stdio.h>
using namespace std;

int main()
{
long double y,d,k,n;

while((scanf("%lf %lf",&n,&k))==2 && n>=1&& k>=0 && k<=n)
{

d=1;
for( y=0;y<=k-1;y++)
d*=(n-y)/(k-y);

printf("%.lf\n",d);
}
return 0;
}

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#include<iostream>
using namespace std;

int main()
{
	long double y,d,k,n;
	while((scanf("%lf %lf",&n,&k))==2 && n>=1&& k>=0 && k<=n)
	{
		d=1;
		for( y=0;y<=k-1;y++)
			d*=(n-y)/(k-y);
		printf("%.lf\n",d);
	}
return 0;
}

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printf("%.lf\n",d);

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printf("%.llf\n",d);