Create sourcema.md

MMzhe · web-flow · commit eb6fc4c431ff · 2019-02-16T15:39:54.000+08:00
diff --git a/2019.01.08-leetcode547/sourcema.md b/2019.01.08-leetcode547/sourcema.md
@@ -0,0 +1,42 @@
+# leetcode 547
+    class Solution {
+    static int[] parent;
+    static int count;
+
+    public static int findCircleNum(int[][] friends) {
+        if (friends == null || friends.length == 0 || friends[0].length == 0) {
+            return 0;
+        }
+        parent = new int[friends.length];
+        count = friends.length;
+        for (int i = 0; i < friends.length; i++) {
+            parent[i] = i;
+        }
+        for (int i = 0; i < friends.length; i++) {
+            for (int j = i+1; j < friends.length; j++) {
+                if (friends[i][j] == 1) {
+                    union(i, j);
+                }
+            }
+        }
+        return count;
+    }
+
+    public static void union(int p, int q) {
+        int rootP = find(p);
+        int rootQ = find(q);
+        if (rootP == rootQ) {
+            return;
+        }
+        parent[rootQ] = rootP;
+        count--;
+    }
+
+    public static int find(int e) {
+        while (parent[e] != e) {
+            parent[e] = parent[parent[e]];//让子节点直接连接父节点
+            e = parent[e];
+        }
+        return e;
+    }
+}
