1480_Running_Sum_of_1d_Array

Author: qiyuangong

README.md

@@ -224,6 +224,7 @@ I'm currently working on [Analytics-Zoo](https://github.com/intel-analytics/anal
 | 1260 | [Shift 2D Grid](https://leetcode.com/problems/shift-2d-grid/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/1260_Shift_2D_Grid.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/1260_Shift_2D_Grid.java) | Final position of each element can be computed according to k, m and n, e.g., k == mn, then don't move, O(mn) and O(mn) |
 | 1337 | [The K Weakest Rows in a Matrix](https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/1337_The_K_Weakest_Rows_in_a_Matrix.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/1337_The_K_Weakest_Rows_in_a_Matrix.java) | Check by row, from left to right, until encount first zero, O(mn) and O(1) |
 | 1365 | [How Many Numbers Are Smaller Than the Current Number](https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/1365_How_Many_Numbers_Are_Smaller_Than_the_Current_Number.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/1365_How_Many_Numbers_Are_Smaller_Than_the_Current_Number.java) | 1. Sort and get position in sorted nums, O(nlogn) and O(n)<br>2. Fill count into 0-100, O(n) and O(1) |
+| 1480 | [Running Sum of 1d Array](https://leetcode.com/problems/running-sum-of-1d-array/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/1480_Running_Sum_of_1d_Array.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/1480_Running_Sum_of_1d_Array.java) | 1. Go through the array, O(n) and O(1)<br>2. Accumulate API |
 
 | # | To Understand |
 |---| ----- |

java/1480_Running_Sum_of_1d_Array.java

@@ -0,0 +1,11 @@
+class Solution {
+    public int[] runningSum(int[] nums) {
+        if (nums.length <= 1) return nums;
+        int accu = nums[0];
+        for (int i = 1; i < nums.length; i++) {
+            accu += nums[i];
+            nums[i] = accu;
+        }
+        return nums;
+    }
+}

python/1480_Running_Sum_of_1d_Array.py

@@ -0,0 +1,11 @@
+class Solution:
+    def runningSum(self, nums: List[int]) -> List[int]:
+        if nums is None or len(nums) == 0:
+            return nums
+        for i in range(1, len(nums)):
+            nums[i] += nums[i-1]
+        return nums
+
+    # def runningSum(self, nums: List[int]) -> List[int]:
+    #     # accumulate method
+    #     return accumulate(nums)