Merge pull request #1199 from xiaofei-2020/back19

添加（0332.重新安排行程.md）：增加typescript版本

problems/0332.重新安排行程.md

@@ -506,6 +506,50 @@ var findItinerary = function(tickets) {
 
 ```
 
+### TypeScript
+
+```typescript
+function findItinerary(tickets: string[][]): string[] {
+    /**
+        TicketsMap 实例：
+        { NRT: Map(1) { 'JFK' => 1 }, JFK: Map(2) { 'KUL' => 1, 'NRT' => 1 } }
+        这里选择Map数据结构的原因是：与Object类型的一个主要差异是，Map实例会维护键值对的插入顺序。
+     */
+    type TicketsMap = {
+        [index: string]: Map<string, number>
+    };
+    tickets.sort((a, b) => {
+        return a[1] < b[1] ? -1 : 1;
+    });
+    const ticketMap: TicketsMap = {};
+    for (const [from, to] of tickets) {
+        if (ticketMap[from] === undefined) {
+            ticketMap[from] = new Map();
+        }
+        ticketMap[from].set(to, (ticketMap[from].get(to) || 0) + 1);
+    }
+    const resRoute = ['JFK'];
+    backTracking(tickets.length, ticketMap, resRoute);
+    return resRoute;
+    function backTracking(ticketNum: number, ticketMap: TicketsMap, route: string[]): boolean {
+        if (route.length === ticketNum + 1) return true;
+        const targetMap = ticketMap[route[route.length - 1]];
+        if (targetMap !== undefined) {
+            for (const [to, count] of targetMap.entries()) {
+                if (count > 0) {
+                    route.push(to);
+                    targetMap.set(to, count - 1);
+                    if (backTracking(ticketNum, ticketMap, route) === true) return true;
+                    targetMap.set(to, count);
+                    route.pop();
+                }
+            }
+        }
+        return false;
+    }
+};
+```
+
 ### Swift
 
 直接迭代tickets数组：