添加（0052.N皇后II.md）：增加typescript版本

Author: xiaofei-2020

problems/0052.N皇后II.md

@@ -144,7 +144,61 @@ var totalNQueens = function(n) {
 };
 ```
 
+TypeScript：
+
+```typescript
+// 0-该格为空，1-该格有皇后
+type GridStatus = 0 | 1;
+function totalNQueens(n: number): number {
+    let resCount: number = 0;
+    const chess: GridStatus[][] = new Array(n).fill(0)
+        .map(_ => new Array(n).fill(0));
+    backTracking(chess, n, 0);
+    return resCount;
+    function backTracking(chess: GridStatus[][], n: number, startRowIndex: number): void {
+        if (startRowIndex === n) {
+            resCount++;
+            return;
+        }
+        for (let j = 0; j < n; j++) {
+            if (checkValid(chess, startRowIndex, j, n) === true) {
+                chess[startRowIndex][j] = 1;
+                backTracking(chess, n, startRowIndex + 1);
+                chess[startRowIndex][j] = 0;
+            }
+        }
+    }
+};
+function checkValid(chess: GridStatus[][], i: number, j: number, n: number): boolean {
+    // 向上纵向检查
+    let tempI: number = i - 1,
+        tempJ: number = j;
+    while (tempI >= 0) {
+        if (chess[tempI][tempJ] === 1) return false;
+        tempI--;
+    }
+    // 斜向左上检查
+    tempI = i - 1;
+    tempJ = j - 1;
+    while (tempI >= 0 && tempJ >= 0) {
+        if (chess[tempI][tempJ] === 1) return false;
+        tempI--;
+        tempJ--;
+    }
+    // 斜向右上检查
+    tempI = i - 1;
+    tempJ = j + 1;
+    while (tempI >= 0 && tempJ < n) {
+        if (chess[tempI][tempJ] === 1) return false;
+        tempI--;
+        tempJ++;
+    }
+    return true;
+}
+```
+
 C
+
 ```c
 //path[i]为在i行，path[i]列上存在皇后
 int *path;