Create Solution.java

Author: Jerring

solution/1128.Number of Equivalent Domino Pairs/Solution.java

@@ -0,0 +1,14 @@
+class Solution {
+    public int numEquivDominoPairs(int[][] dominoes) {
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int[] d : dominoes) {
+            int x = d[0] < d[1] ? d[0] * 10 + d[1] : d[1] * 10 + d[0];
+            map.put(x, map.getOrDefault(x, 0) + 1);
+        }
+        int res = 0;
+        for (int v : map.values()) {
+            res += v * (v - 1) / 2;
+        }
+        return res;
+    }
+}