add: Course Schedule II

Author: hijiangtao

src/course-schedule-ii/res.js

@@ -24,69 +24,69 @@
  * @return {number[]}
  */
 let findOrder = function(numCourses, prerequisites) {
-    let prelen = prerequisites.length,
-        maxNoCircle = numCourses * (numCourses - 1) / 2;
-    // 当所有点都有边连接时, 最大的无环边数
-    if (prelen > maxNoCircle) {
-        return [];
-    }
+	let prelen = prerequisites.length,
+		maxNoCircle = numCourses * (numCourses - 1) / 2;
+	// 当所有点都有边连接时, 最大的无环边数
+	if (prelen > maxNoCircle) {
+		return [];
+	}
 
-    let queue = [], // 存储 BFS 待访问节点序列
-        flags = [], // 存储节点是否被访问过的标记
-        res = [], //结果
-        nodedegree = new Array(numCourses), // 存储node的连边总数
-        edges = new Array(numCourses); // 存储连边信息, 每个元素中存储的数组表示自己的后续课程
-    for (let i = 0; i < numCourses; i++) {
-        flags[i] = false;
-        nodedegree[i] = 0;
-        edges[i] = [];
-    }
+	let queue = [], // 存储 BFS 待访问节点序列
+		flags = [], // 存储节点是否被访问过的标记
+		res = [], //结果
+		nodedegree = new Array(numCourses), // 存储node的连边总数
+		edges = new Array(numCourses); // 存储连边信息, 每个元素中存储的数组表示自己的后续课程
+	for (let i = 0; i < numCourses; i++) {
+		flags[i] = false;
+		nodedegree[i] = 0;
+		edges[i] = [];
+	}
 
-    for (let i = 0; i < prelen; i++) {
-        let source = prerequisites[i][0],
-            target = prerequisites[i][1];
+	for (let i = 0; i < prelen; i++) {
+		let source = prerequisites[i][0],
+			target = prerequisites[i][1];
 
-        edges[target].push(source);
-        nodedegree[source]++;
-        nodedegree[target]++;
-    }
-    
-    for (let i = 0; i < numCourses; i++) {
-        if (nodedegree[i] === edges[i].length) {
-            queue.push(i);
-        }
-    }
-    
-    if (bfsVisit()) {
-        return res;
-    } else {
-        return [];
-    }
-    
-    function bfsVisit() {
-        while (queue.length) {
-            let current = queue.shift(), //当前访问节点
-                elen = edges[current].length; // 边数
-            
-            res.push(current);
-            // console.log(current, res);
-            flags[current] = true;
-            for (let i=0; i<elen; i++) {
-                let target = edges[current][i];
-                if (flags[target]) {
-                     return false; // 有回路,返回 false
-                }
-                if (--nodedegree[target] === edges[target].length) {
-                    queue.push(target);
-                }
-            }
-            edges[current] = [];
-            nodedegree[current] -= elen;
-        }
-        
-        if (res.length < numCourses) {
-            return false;
-        }
-        return true;
-    }
-};
+		edges[target].push(source);
+		nodedegree[source]++;
+		nodedegree[target]++;
+	}
+
+	for (let i = 0; i < numCourses; i++) {
+		if (nodedegree[i] === edges[i].length) {
+			queue.push(i);
+		}
+	}
+
+	if (bfsVisit()) {
+		return res;
+	} else {
+		return [];
+	}
+
+	function bfsVisit() {
+		while (queue.length) {
+			let current = queue.shift(), //当前访问节点
+				elen = edges[current].length; // 边数
+
+			res.push(current);
+			// console.log(current, res);
+			flags[current] = true;
+			for (let i = 0; i < elen; i++) {
+				let target = edges[current][i];
+				if (flags[target]) {
+					return false; // 有回路,返回 false
+				}
+				if (--nodedegree[target] === edges[target].length) {
+					queue.push(target);
+				}
+			}
+			edges[current] = [];
+			nodedegree[current] -= elen;
+		}
+
+		if (res.length < numCourses) {
+			return false;
+		}
+		return true;
+	}
+};