724. Find Pivot Index

Input: 
nums = [1, 7, 3, 6, 5, 6]
Output: 3
Explanation: 
The sum of the numbers to the left of index 3 (nums[3] = 6) is equal to the sum of numbers to the right of index 3.
Also, 3 is the first index where this occurs.

Input: 
nums = [1, 2, 3]
Output: -1
Explanation: 
There is no index that satisfies the conditions in the problem statement.

class Solution {
    public int pivotIndex(int[] nums) {
        int pivot = -1;
        
        for(int i=0; i<nums.length; i++){
            int sum1 = 0;
            int sum2 = 0;
            
            for(int m=0; m<i; m++){
                sum1 += nums[m];
            }
            for(int n=i+1; n<nums.length; n++){
                sum2 += nums[n];
            }
            
            if(sum1 == sum2){
                pivot = i;
                break;
            }
        }
        
        return pivot;
    }
}

class Solution {
    public int pivotIndex(int[] nums) {
        int pivot = -1;
        
        int sum = 0;
        int comp = 0;
        
        for(int num : nums){
            sum += num;
        }
        
        for(int i=0; i<nums.length; i++){
            if(comp == sum - comp - nums[i]){
                return i;
            }
            comp += nums[i];
        }
        
        return pivot;
    }
}

[문제] https://leetcode.com/problems/find-pivot-index/