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;
    }
}

@@ -99,36 +99,8 @@
 ms;%0A
-        int accu = nums%5B0%5D;%0A
     
@@ -140,18 +140,16 @@
 th; i++)
- %7B
 %0A       
@@ -157,62 +157,31 @@
     
-accu += nums%5Bi%5D;%0A            nums%5Bi%5D = accu;%0A        %7D
+nums%5Bi%5D += nums%5Bi - 1%5D;
 %0A   

Remove accu in 1480_Running_Sum_of_1d_Array