LeetCode 001_Two Sum Java

標籤：leetcode   hashmap   java   

public class Solution {    public int[] twoSum(int[] nums, int target) {        int temp;        boolean flag = false;        int[] index = new int[2];        for(int i = 0; i < nums.length; i++){            temp = target - nums[i];            for(int j = 0; j < nums.length; j++){            if(i == j) continue;                if(temp == nums[j]){                    index[1] = j+1;                    flag = true;                    break;                }            }            if(flag){                index[0] = i+1;                break;               }        }        return index;    }  思路二： 把數組的值作為map的key， 由於滿足 nums[i] + nums[j] = target ,故必存在key值滿足nums的元素    public int[] twoSum2(int[] nums, int target) {            int[] index=new int[2];          HashMap<Integer,Integer> hm = new HashMap<Integer,Integer>();                    for(int i = 0; i<nums.length; i++)          {              if(hm.containsKey(target - nums[i]))              {                  index[1] = i+1;                  index[0] = hm.get(target-nums[i])+1;                     return index;                 }else              {                   hm.put(nums[i],i);              }          }          return index;        }  }

LeetCode 001_Two Sum Java