303.区域和检索-数组不可变

/*
 * @lc app=leetcode.cn id=303 lang=typescript
 *
 * [303] 区域和检索 - 数组不可变
 */

// @lc code=start
class NumArray {
	private nums: number[];
	constructor(nums: number[]) {
		this.nums = nums;
	}
	sumRange(left: number, right: number): number {
		let total: number = 0;
		this.nums.map((num, index) => {
			if (index >= left && index <= right) {
				total += num;
			}
		});

		return total;
	}
}

/**
 * Your NumArray object will be instantiated and called as such:
 * var obj = new NumArray(nums)
 * var param_1 = obj.sumRange(left,right)
 */
// @lc code=end