[Java] Simple two pointers solution
Intuition\n Describe your first thoughts on how to solve this problem. \nJust follow the steps in the problem.\n\n# Approach\n Describe your approach to solving
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\nJust follow the steps in the problem.\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\nUse two pointers to mark the first and last number.\n\n# Complexity\n- Time complexity: $$O(N)$$\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity: $$O(1)$$\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\n  public long findTheArrayConcVal(int[] nums) {\n    long result = 0;\n    int left = 0;\n    int right = nums.length - 1;\n    while (left <= right) {\n      if (left == right) {\n        result += nums[left];\n      } else {\n        long shift = 1;\n        int num = nums[right];\n        while (num != 0) {\n          shift *= 10;\n          num /= 10;\n        }\n\n        result += shift * nums[left] + nums[right];\n      }\n      right--;\n      left++;\n    }\n\n    return result;\n  }\n}\n\n```
['Two Pointers', 'Java']