[algorithm] sword finger offer2 golang interview question 12: the sum of the left and right sub arrays is equal

[ Algorithm ] The finger of the sword offer2 golang Interview questions 12： The sum of the left and right subarrays is equal

subject 1:

Ideas 1:

// Ideas : 
//1. Record the total number  sum
//2. Traversal element calculation  sum - nums[i] - leftSum == leftSum ,return i 

Code

func pivotIndex(nums []int) int {
    
    //start: 13.16 end: 13.22
    // Ideas : 
    //1. Record the total number  sum
    //2. Traversal element calculation  sum - nums[i] - leftSum == leftSum ,return i 

    // Processing parameters 
    if len(nums) == 0 {
    
        return -1
    }

    //1. Record the total number  sum
    sum := 0 
    for i := 0; i < len(nums); i++{
    
        sum += nums[i]
    }

    //2. Traverse the element to find the center point 
    leftSum := 0 
    for i := 0; i < len(nums); i++{
    
        //(1)  Judge 
        if sum - nums[i] - leftSum == leftSum{
    
            return i
        }
        // Fail to judge 
        leftSum += nums[i]
    }

    return -1
}

test