42 lines
1.0 KiB
C++
42 lines
1.0 KiB
C++
/** The sequence of triangle numbers is generated by adding the natural numbers. So the 7th 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? */
|
|
|
|
#include "0.hpp"
|
|
|
|
int main()
|
|
{
|
|
uu n = 1;
|
|
uu max;
|
|
uu sqr;
|
|
timeb start, now;
|
|
ftime(&start);
|
|
do {
|
|
max = n * (n + 1) / 2;
|
|
sqr = (uu)(sqrt((double)max));
|
|
int count = 0;
|
|
uu temp = 1;
|
|
while(temp < sqr) {
|
|
if(max % temp == 0) count++;
|
|
temp++;
|
|
}
|
|
ftime(&now);
|
|
if(count >= 250) {
|
|
cout << n << " " << max << " time: " << (now.time * 1000 + now.millitm - start.time * 1000 - start.millitm) << "ms" << endl;
|
|
break;
|
|
}
|
|
n++;
|
|
} while(1);
|
|
|
|
return 0;
|
|
}
|