2562. 找出数组的串联值

题目

题解

• 直接使用双指针，依次拼接
• 如果指针结束指向同一个数，则再加上该数

class Solution {
    public long findTheArrayConcVal(int[] nums) {

        int left = 0;
        int right = nums.length - 1;
        long res = 0;
        while (right > left) {
            int lv = nums[left];
            int rv = nums[right];
            while (rv > 0) {
                rv = rv / 10;
                lv = lv * 10;
            }
            res = res + lv + nums[right];

            left++;
            right--;
        }

        if (left == right) {
            return res + nums[left];
        }

        return res;

    }
}