LeetCode ---- Two Sum (Java Lua 实现)

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题目:

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution.

Example:

Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,return [0, 1].

UPDATE (2016/2/13):
The return format had been changed to zero-based indices. Please read the above updated description carefully.


Java 实现:

public class Solution {    public int[] twoSum(int[] nums, int target) {        int[] result = null;        for (int i = 0; i < nums.length; i++) {            for (int j = i + 1; j < nums.length; j++) {                if (nums[i] + nums[j] == target) {                    result = new int[2];                    result[0] = i;                    result[1] = j;                }            }        }        return result;    }}


Lua 实现:

function twoSum(nums, target)        assert(type(nums) == "table", "nums 不是 table 类型")        assert(type(target) == "number", "target 不是 数字")        for i = 1, #nums do            for j = i + 1, #nums+1 do                if (nums[i] + nums[j] == target) then                    return {i, j}                end            end        endendnums = {1,2,3,4,5,6,7,8,9}target = 10result = twoSum(nums,target)print(result[1])print(result[2])



因为主要是为了练习 Lua 的语法,所以说一下在写过程经常遗漏的东西:
  • Lua 数组下标是从 1 开始的,而 Java 是从 0 开始的,笔者没注意还是用 0 导致执行报错(lua: twoSum.lua:18: attempt to perform arithmetic on field '?' (a nil value) stack traceback:  twoSum.lua:18: in main chunk  [C]: ? )
  • for 和 if 后面有 do 关键字

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