Maximum Product Subarray

class Solution {
public:
    int maxProduct(vector<int>& nums) {
        int curMax = nums[0], curMin = nums[0], best = nums[0];
        for (int i = 1; i < (int)nums.size(); ++i) {
            int x = nums[i];
            if (x < 0) swap(curMax, curMin);
            curMax = max(x, curMax * x);
            curMin = min(x, curMin * x);
            best = max(best, curMax);
        }
        return best;
    }
};

func maxProduct(nums []int) int {
    curMax, curMin, best := nums[0], nums[0], nums[0]
    for i := 1; i < len(nums); i++ {
        x := nums[i]
        if x < 0 {
            curMax, curMin = curMin, curMax
        }
        if x > curMax*x {
            curMax = x
        } else {
            curMax = curMax * x
        }
        if x < curMin*x {
            curMin = x
        } else {
            curMin = curMin * x
        }
        if curMax > best {
            best = curMax
        }
    }
    return best
}

from typing import List

class Solution:
    def maxProduct(self, nums: List[int]) -> int:
        cur_max = cur_min = best = nums[0]
        for x in nums[1:]:
            if x < 0:
                cur_max, cur_min = cur_min, cur_max
            cur_max = max(x, cur_max * x)
            cur_min = min(x, cur_min * x)
            best = max(best, cur_max)
        return best

function maxProduct(nums) {
    let curMax = nums[0], curMin = nums[0], best = nums[0];
    for (let i = 1; i < nums.length; i++) {
        const x = nums[i];
        if (x < 0) [curMax, curMin] = [curMin, curMax];
        curMax = Math.max(x, curMax * x);
        curMin = Math.min(x, curMin * x);
        best = Math.max(best, curMax);
    }
    return best;
}

class Solution {
    public int maxProduct(int[] nums) {
        int curMax = nums[0], curMin = nums[0], best = nums[0];
        for (int i = 1; i < nums.length; i++) {
            int x = nums[i];
            if (x < 0) {
                int tmp = curMax;
                curMax = curMin;
                curMin = tmp;
            }
            curMax = Math.max(x, curMax * x);
            curMin = Math.min(x, curMin * x);
            best = Math.max(best, curMax);
        }
        return best;
    }
}

function maxProduct(nums: number[]): number {
    let curMax = nums[0], curMin = nums[0], best = nums[0];
    for (let i = 1; i < nums.length; i++) {
        const x = nums[i];
        if (x < 0) [curMax, curMin] = [curMin, curMax];
        curMax = Math.max(x, curMax * x);
        curMin = Math.min(x, curMin * x);
        best = Math.max(best, curMax);
    }
    return best;
}