Golang | Leetcode Golang题解之第303题区域和检索-数组不可变

题目：

题解：

type NumArray struct {
    sums []int
}

func Constructor(nums []int) NumArray {
    sums := make([]int, len(nums)+1)
    for i, v := range nums {
        sums[i+1] = sums[i] + v
    }
    return NumArray{sums}
}

func (na *NumArray) SumRange(i, j int) int {
    return na.sums[j+1] - na.sums[i]
}