1634 = 14 + 64 + 34 + 44
8208 = 84 + 24 + 04 + 84
9474 = 94 + 44 + 74 + 44
1 = 14沒有被算作在內因爲它不是一個和。
這些數字的和是 1634 + 8208 + 9474 = 19316.
找出所有能被寫成各位數字五次方之和的數之和。
從10開始到 5個9^5結束~~
public class Problem30
{
public static void main(String[] args)
{
long start = System.currentTimeMillis();
System.out.print("answer: ");
howmany();
long end = System.currentTimeMillis();
System.out.print("time: ");
System.out.println(end - start);
}
static void howmany()
{
int sum = 0;
int max = 0;
for (int i = 0; i < 5; i++)
{
max += Math.pow(9, 5);
}
for (int i = 10; i <= max; i++)
{
int s = 0;
int t = i;
while (t != 0)
{
s += Math.pow(t % 10, 5);
t /= 10;
}
if (s == i)
{
sum += i;
}
}
System.out.println(sum);
}
}
answer: 443839
time: 352