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Java Solution for LeetCode algorithm problems, continually updating
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package g0401_0500.s0447_number_of_boomerangs;
// #Medium #Array #Hash_Table #Math #2022_06_03_Time_156_ms_(80.44%)_Space_109.2_MB_(69.17%)
import java.util.HashMap;
public class Solution {
public int numberOfBoomerangs(int[][] points) {
HashMap m = new HashMap<>();
int ans = 0;
for (int i = 0; i < points.length; i++) {
for (int j = 0; j < points.length; j++) {
if (i == j) {
continue;
}
int dis = dist(points[i], points[j]);
int prev = m.getOrDefault(dis, 0);
if (prev >= 1) {
ans += prev * 2;
}
m.put(dis, prev + 1);
}
m.clear();
}
return ans;
}
private int dist(int[] d1, int[] d2) {
return (d1[0] - d2[0]) * (d1[0] - d2[0]) + (d1[1] - d2[1]) * (d1[1] - d2[1]);
}
}