LeetCode - Running Sum Of 1d Array

題目

  • inputs nums 是一個陣列
  • outputs 的結果是 runningSum[i] = sum(nums[0]…nums[i])

example

Input: nums = [1,2,3,4]
Output: [1,3,6,10]
Explanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].

思考

  • iteration, 不可以超過 nums length
  • 儲存加起來的值
  • -> index[0] 不動 -> index[1] = index[0] + index[1]
  • -> index[1] 不動 -> index[2] = index[1] + index[2]
  • …
  • index[i + 1] = index[i] + index [i+1]
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function sum(nums) {
  for (let i = 0; i < nums.length - 1; i++) {
    let temp = nums[i] + nums[i + 1]
    nums[i + 1] = temp
  }
  return nums
}
let nums = [1, 2, 3, 4]
console.log(sum(nums))