public class VampireNum {
public static void main(String[] args) {
int i, a, b, c, d;
for (i = 1111; i <= 9999; i++) {
if (i % 100 != 0) {
a = i / 1000;
b = i / 100 % 10;
c = i / 10 % 10;
d = i % 10;
if ((a > 0 && c > 0) && (a * 10 + b) * (c * 10 + d) == i
|| (a * 10 + d) * (c * 10 + b) == i) {
System.out.println(i);
}
if ((a > 0 && b > 0) && (a * 10 + c) * (b * 10 + d) == i
|| (a * 10 + d) * (b * 10 + c) == i) {
System.out.println(i);
}
if ((a > 0 && d > 0) && (a * 10 + b) * (d * 10 + c) == i
|| (a * 10 + c) * (d * 10 + a) == i) {
System.out.println(i);
}
if ((b > 0 && c > 0) && (b * 10 + a) * (c * 10 + d) == i
|| (b * 10 + d) * (c * 10 + a) == i) {
System.out.println(i);
}
if ((b > 0 && d > 0) && (b * 10 + a) * (d * 10 + c) == i
|| (b * 10 + c) * (d * 10 + a) == i) {
System.out.println(i);
}
if ((c > 0 && d > 0) && (d * 10 + b) * (c * 10 + a) == i
|| (d * 10 + a) * (c * 10 + b) == i) {
System.out.println(i);
}
}
} }
}结果:
1260
1395
1435
1530
1827
2187
6880
求优化!
public static void main(String[] args)
{
for (int i = 10; i<100; i++)
{
for (int j = 10; j<=i; j++)
{
String s1 = String.valueOf(i)+String.valueOf(j);
char[] a1 = s1.toCharArray();
Arrays.sort(a1);
String s2 = String.valueOf(i*j);
char[] a2 = s2.toCharArray();
Arrays.sort(a2);
if (Arrays.toString(a1).equals(Arrays.toString(a2)))
{
System.out.printf("%d*%d=%d\n", i, j, i*j);
}
}
}
}
int z;
outer: for (int y = Math.max(x, 1000 / x); y <= 99 && (z = x * y) <= 9999; y++) {
if (z < 1000) {
continue;
}
int[] count1 = new int[10];
int[] count2 = new int[10];
count1[z / 1000]++;
count1[z % 1000 / 100]++;
count1[z % 100 / 10]++;
count1[z % 10]++;
count2[x/10]++;
count2[x%10]++;
count2[y/10]++;
count2[y%10]++;
for (int i = 0; i < count1.length; i++) {
if (count1[i] != count2[i]) {
continue outer;
}
}
System.out.printf("%d * %d = %d%n", x, y, z);
}
}
我虽然是for嵌套,遍历x,y,lz是单层for遍历z,但实际上循环次数比lz少,lz是九千次,我才三千多
用这个测的值 怎么你的还会比我的高呢?