feat: add typescript solution to lc problem: No.0907

No.0907.Sum of Subarray Minimums

Author: zhaocchen

solution/0900-0999/0907.Sum of Subarray Minimums/README.md

@@ -61,6 +61,29 @@
 
 ```
 
+### **TypeScript**
+
+```ts
+function sumSubarrayMins(arr: number[]): number {
+    const n = arr.length;
+    function getEle(i: number): number {
+        if (i == -1 || i == n) return Number.MIN_SAFE_INTEGER;
+        return arr[i];
+    }
+    let ans = 0;
+    const mod = 10 ** 9 + 7;
+    let stack = [];
+    for (let i = -1; i <= n; i++) {
+        while (stack.length && getEle(stack[0]) > getEle(i)) {
+            const idx = stack.shift();
+            ans = (ans + arr[idx] * (idx - stack[0]) * (i - idx)) % mod;
+        }
+        stack.unshift(i);
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/0900-0999/0907.Sum of Subarray Minimums/README_EN.md

@@ -49,6 +49,29 @@ Sum is 17.
 
 ```
 
+### **TypeScript**
+
+```ts
+function sumSubarrayMins(arr: number[]): number {
+    const n = arr.length;
+    function getEle(i: number): number {
+        if (i == -1 || i == n) return Number.MIN_SAFE_INTEGER;
+        return arr[i];
+    }
+    let ans = 0;
+    const mod = 10 ** 9 + 7;
+    let stack = [];
+    for (let i = -1; i <= n; i++) {
+        while (stack.length && getEle(stack[0]) > getEle(i)) {
+            const idx = stack.shift();
+            ans = (ans + arr[idx] * (idx - stack[0]) * (i - idx)) % mod;
+        }
+        stack.unshift(i);
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/0900-0999/0907.Sum of Subarray Minimums/Solution.ts

@@ -0,0 +1,18 @@
+function sumSubarrayMins(arr: number[]): number {
+    const n = arr.length;
+    function getEle(i: number): number {
+        if (i == -1 || i == n) return Number.MIN_SAFE_INTEGER;
+        return arr[i];
+    }
+    let ans = 0;
+    const mod = 10 ** 9 + 7;
+    let stack = [];
+    for (let i = -1; i <= n; i++) {
+        while (stack.length && getEle(stack[0]) > getEle(i)) {
+            const idx = stack.shift();
+            ans = (ans + arr[idx] * (idx - stack[0]) * (i - idx)) % mod;
+        }
+        stack.unshift(i);
+    }
+    return ans;
+};