package _3sum;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
public class Solution {
public List> threeSum(int[] num) {
Arrays.sort(num);
List
> result = new LinkedList<>();
for (int i = num.length - 1; i > 1; i--) {
if (i + 1 < num.length && num[i] == num[i + 1]) {
continue;
}
for (int j = 0, k = i - 1; j < k; ) {
int sum = num[j] + num[k] + num[i];
if (sum < 0) {
j++;
} else if (sum > 0) {
k--;
} else {
result.add(Arrays.asList(num[j], num[k], num[i]));
do {
j++;
k--;
} while (j < k && num[j - 1] == num[j] && num[k] == num[k + 1]);
}
}
}
return result;
}
public static void main(String[] args) {
System.out.println(new Solution().threeSum(new int[]{0, 0, 0, 0, 0, 0, 0}));
}
}