[Leetcode] 307. Range Sum query-mutable

Given an integer array nums, find the sum of the elements between indices I and J (i ≤ J), inclusive.

the update (I, Val) function modifies nums by updating the element on index i to Val.

Example:

Given nums = [1, 3, 5]sumrange (0, 2), 9update (1, 2) sumrange (0, 2), 8

Note:

1. The array is a modifiable by the update function.
2. Assume the number of calls to update and sumrange function is distributed evenly.

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Solution:

Using values and sums to record the first n and, respectively, Nums and Nums, and, when update, the index of the sums is greater than I will change.

1 classNumarray2 {3  Public:4Numarray (vector<int> &nums)5     {6Sums.push_back (0);7          for(inti =0; I < nums.size (); i++)8         {9Sums.push_back (Sums[i] +nums[i]);Ten Values.push_back (Nums[i]); One         } A     } -  -     voidUpdateintIintval) the     { -         intdiff = Val-Values[i]; -          for(intK = i +1; K < Sums.size (); k++) -SUMS[K] = Sums[k] +diff; +Values[i] =Val; -     } +  A     intSumrange (intIintj) at     { -         returnSums[j +1] -Sums[i]; -     } - Private: -vector<int>sums; -vector<int>values; in};

[Leetcode] 307. Range Sum query-mutable