g2001_2100.s2094_finding_3_digit_even_numbers.Solution Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-java11 Show documentation
Show all versions of leetcode-in-java11 Show documentation
Java Solution for LeetCode algorithm problems, continually updating
The newest version!
package g2001_2100.s2094_finding_3_digit_even_numbers;
// #Easy #Array #Hash_Table #Sorting #Enumeration
// #2022_05_23_Time_2_ms_(99.62%)_Space_44.9_MB_(69.58%)
import java.util.Arrays;
public class Solution {
public int[] findEvenNumbers(int[] digits) {
int[] idx = new int[1];
int[] result = new int[9 * 10 * 5];
int[] digitMap = new int[10];
for (int digit : digits) {
digitMap[digit]++;
}
dfs(result, digitMap, idx, 0);
return Arrays.copyOfRange(result, 0, idx[0]);
}
private void dfs(int[] result, int[] digitMap, int[] idx, int val) {
if (val > 99) {
result[idx[0]++] = val;
return;
}
val *= 10;
for (int i = 0; i < 10; i++) {
if (digitMap[i] == 0 || (val == 0 && i == 0) || (val > 99 && (i & 1) == 1)) {
continue;
}
digitMap[i]--;
val += i;
dfs(result, digitMap, idx, val);
val -= i;
digitMap[i]++;
}
}
}