Li Kou daily question - Day 32 -1822 Symbol of array element product

2022.6.30 Did you brush the questions today ？

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subject ：

Known functions  signFunc(x) Will be based on x The positive and negative of returns a specific value ：

If x Positive number , return 1 .
If x It's a negative number , return -1 .
If x Is equal to 0 , return 0 .
Give you an array of integers nums . Make product Is an array nums The product of the values of all elements in .

return signFunc(product) .

analysis ：

Give you an array , Multiply all the elements of the array to get ans, And then determine ans The corresponding value is output in the positive and negative relationship of .

Ideas ： You can't multiply the result directly here （ Because the title requires ）, So let's change our mind , As long as the element is judged inside =0, Then go straight back 0, If there are negative numbers in the element , Record once , Finally, we only need to judge the number of negative numbers to output the results .

analysis ：

1. Violent solution

class Solution {
public:
    int arraySign(vector<int>& nums) {
        bool sum = true;
        for (auto num : nums)
        {
            if (num == 0)
            {
                return 0;
            }
            if (num < 0)
            {
                sum = !sum;
            }
 
        }
        return sum ? 1 : -1;

    }
};