添加（0056.合并区间.md）：增加typescript版本

problems/0056.合并区间.md

@@ -266,6 +266,26 @@ var merge = function(intervals) {
 };
 ```
 
+### TypeScript
+
+```typescript
+function merge(intervals: number[][]): number[][] {
+    const resArr: number[][] = [];
+    intervals.sort((a, b) => a[0] - b[0]);
+    resArr[0] = [...intervals[0]];  // 避免修改原intervals
+    for (let i = 1, length = intervals.length; i < length; i++) {
+        let interval: number[] = intervals[i];
+        let last: number[] = resArr[resArr.length - 1];
+        if (interval[0] <= last[1]) {
+            last[1] = Math.max(interval[1], last[1]);
+        } else {
+            resArr.push([...intervals[i]]);
+        }
+    }
+    return resArr;
+};
+```
+
 
 
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