题解 | #牛群重量积#

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param nums int整型一维数组 
 * @return int整型一维数组
 */
function productExceptSelf(nums) {
    // write code here
    let res = []
    for (let i = 0; i < nums.length; i++) {
        let item = null
        if (i === 0) {
            item = nums.slice(i + 2).reduce((a, b) => a * b)
        } else if (i === nums.length - 1) {
            item = nums.slice(0,i - 1).reduce((a, b) => a * b)
        } else {
            let left = 1
            let right = 1

            if (nums[i - 2]) {
                let leftArr = nums.slice(0,i - 1)
                left = leftArr.length > 0 ? leftArr.reduce((a, b) => a * b) : nums[i - 2]

            }
            if (nums[i + 2]) {
                let rightArr = nums.slice(i + 2)
                right = rightArr.length > 0 ? rightArr.reduce((a, b) => a * b) : nums[i + 2]
            }

            item = left * right
        }
        console.log("i", i, item)
        res.push(item)
    }

    return res
}
module.exports = {
    productExceptSelf: productExceptSelf
};