（Problem 5）Smallest multiple

2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.

What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

#include <stdio.h>

#include <string.h>

#include <ctype.h>

#include <math.h>

  

#define N 20

  

int gcd(int a, int b)

{

  if(b==0)

    return a;

  else

    return gcd(b,a%b);

}

  

int lcm(int a, int b)

{

  return a/(gcd(a,b))*b;

}

  

  

void solve()

{

   int i,s=2;

   for(i=3; i<=N; i++)

   {

      s=lcm(s,i);

   }

   printf("%d\n",s);

}

  

int main()

{

  solve();

  return 0;

}

Answer:

232792560