Problem 12
Statement
The sequence of triangle numbers is generated by adding the natural numbers. So the 7^(th) triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …
Let us list the factors of the first seven triangle numbers:
1: 1
3: 1,3
6: 1,2,3,6
10: 1,2,5,10
15: 1,3,5,15
21: 1,3,7,21
28: 1,2,4,7,14,28
We can see that 28 is the first triangle number to have over five divisors.
What is the value of the first triangle number to have over five hundred divisors?
Solution
The code, in C.
#include <stdio.h>
int triNum(int max)
{
int div=0,i,m=0,n=1,a=0;
while(div<max){
m+=n;
n++;
div=0;
a=m;
for(i=1;i<a;i++)
if(m%i==0){
div+=2;
a=m/i;
}
}
return m;
}
int main(void)
{
printf("%d\n",triNum(500));
return 0;
}
Answer
76576500
SPEAK / ADD YOUR COMMENT
Comments are moderated.
Posts