Update 1203-sort-items-by-groups-respecting-dependencies.js

Author: everthis

1203-sort-items-by-groups-respecting-dependencies.js

@@ -1,3 +1,52 @@
+/**
+ * @param {number} n
+ * @param {number} m
+ * @param {number[]} group
+ * @param {number[][]} beforeItems
+ * @return {number[]}
+ */
+const sortItems = function (n, m, group, beforeItems) {
+  const graph = Array.from({ length: m + n }, () => [])
+  const indegree = Array(n + m).fill(0)
+  for (let i = 0; i < group.length; i++) {
+    if (group[i] == -1) continue
+    graph[n + group[i]].push(i)
+    indegree[i]++
+  }
+  for (let i = 0; i < beforeItems.length; i++) {
+    for (let e of beforeItems[i]) {
+      let a = group[e] === -1 ? e : n + group[e]
+      let b = group[i] === -1 ? i : n + group[i]
+      if (a === b) {
+        // same group, ingroup order
+        graph[e].push(i)
+        indegree[i]++
+      } else {
+        // outgoup order
+        graph[a].push(b)
+        indegree[b]++
+      }
+    }
+  }
+  const res = []
+  for (let i = 0; i < n + m; i++) {
+    if (indegree[i] === 0) dfs(res, graph, indegree, n, i)
+  }
+  return res.length === n ? res : []
+
+  function dfs(ans, graph, indegree, n, cur) {
+    if (cur < n) ans.push(cur)
+    indegree[cur] = -1 // mark it visited
+    for (let next of graph[cur] || []) {
+      indegree[next]--
+      if (indegree[next] === 0) dfs(ans, graph, indegree, n, next)
+    }
+  }
+}
+
+// another
+
+
 /**
  * @param {number} n
  * @param {number} m