https://leetcode.cn/problems/tree-of-coprimes/

Author: masx200

README.md

@@ -10,6 +10,8 @@ leetcode 测试
 
 ##### 包含的内容如下
 
+https://leetcode.cn/problems/tree-of-coprimes/
+
 https://leetcode.cn/problems/check-if-all-characters-have-equal-number-of-occurrences/
 
 https://leetcode.cn/problems/cyJERH/

tree-of-coprimes/index.ts

@@ -0,0 +1,51 @@
+export default getCoprimes;
+function getCoprimes(nums: number[], edges: number[][]): number[] {
+    const edge = Array(nums.length)
+        .fill(0)
+        .map(() => Array<number>());
+    for (const [a, b] of edges) {
+        edge[a].push(b);
+        edge[b].push(a);
+    }
+
+    if (prime.length === 0) {
+        for (const i of Array(51).keys()) {
+            prime[i] = Array(51).fill(false);
+        }
+
+        for (const i of Array(51).keys())
+            for (let j = i; j < 51; j++) {
+                prime[i][j] = prime[j][i] = greatestCommonDivisor(i, j) === 1;
+            }
+    }
+
+    const visited = new Set<number>();
+    function dfs(node: number, ancestors: number[]) {
+        if (!visited.has(node)) {
+            visited.add(node);
+
+            if (ancestors.length) {
+                for (let i = ancestors.length - 1; i >= 0; i--) {
+                    if (prime[nums[node]][nums[ancestors[i]]]) {
+                        results[node] = ancestors[i];
+                        break;
+                    }
+                }
+            }
+            for (const child of edge[node]) {
+                ancestors.push(node);
+                dfs(child, ancestors);
+                ancestors.pop();
+            }
+        }
+    }
+    const results: number[] = Array(nums.length).fill(-1);
+    dfs(0, []);
+    return results;
+}
+
+const prime: boolean[][] = [];
+
+function greatestCommonDivisor(a: number, b: number): number {
+    return b != 0 ? greatestCommonDivisor(b, a % b) : a;
+}