## [1. 两数之和](https://leetcode.cn/problems/two-sum/)
### 解法1,利用HashMap(map.get(Key))实现数的存储和输出
```java
class Solution {
public int[] twoSum(int[] nums, int target) {
Map<integer,integer> map = new HashMap<>();
int[] ints = new int[2];
for (int i = 0; i < nums.length; i++) {
int goal_num=target-nums[i];
if (map.containsKey(goal_num)){
ints[0]=i;
ints[1]=map.get(goal_num);
break;
}
map.put(nums[i],i);
}
return ints;
}
}
```
#### 思路
1. 是对于hashmap的利用，即利用其key和value的特性，达到二维数组的存储效果，存储两个数值
2. 是哈希表的优势就在于O（1）的查找，利用map.get(Key)函数,可以直接实现目标数的查找
3. 就是对于题意的理解，寻找两数之和翻译过后的意思其实是寻找目标值target作差后值的数字
即int goal_num=target-nums[i]；
#### 参考资料
[ACM 选手图解 LeetCode 两数之和 | 编程文青李狗蛋](https://leetcode.cn/problems/two-sum/solution/acm-xuan-shou-tu-jie-leetcode-liang-shu-3rf9r/)
[「代码随想录」梦开始的地方！](https://leetcode.cn/problems/two-sum/solution/by-carlsun-2-sarb/)
### 解法2:暴力解法
思路:两层，外层取遍历nums[i]，内层遍历nums[i+1]，再一个if，直接解决……(够无脑哈哈……)
```java
class Solution {
public int[] twoSum(int[] nums, int target) {
int[] ints = new int[2];
for (int i = 0; i < nums.length; i++) {
for (int j = i + 1; j < nums.length; j++) {
if (nums[i] + nums[j] == target) {
ints[0] = i;
ints[1] = j;
break;
}
}
}
return ints;
}
}
```
## [242. 有效的字母异位词](https://leetcode.cn/problems/valid-anagram/)
### 解法1: 利用哈希映射将存储元素进行比较
```java
class Solution {
public boolean isAnagram(String s, String t) {
int[] record = new int[26];
if (s.length()!=t.length()){
return false;
} //basecase
for (int i = 0; i <s.length() ;="" i++)="" {="" char="" c="s.charAt(i);//String转char" record[c-'a']++;="" char转int="" }="" for="" (int="" i="0;" <t.length()="" record[c-'a']--;="" (integer="" :="" record)="" if="" (i!="0){" return="" false;="" true;="" ```="" ###="" 解法2:排序，然后直接遍历="" ```java="" class="" solution="" public="" boolean="" isanagram(string="" s,="" string="" t)="" if(s.length()!="t.length()){" char[]="" char_s="s.toCharArray();" char_t="t.toCharArray();" arrays.sort(char_s);="" arrays.sort(char_t);="" int="" for_length="Math.min(s.length(),t.length());" <for_length;="" (char_s[i]!="char_t[i]){" ####="" 思路:="" ![image-20230123180140059](http:="" 150154.xyz="" 2023="" 1="" image-20230123180140059.png)="" 资料：="" #="" <img="" src="">
[「代码随想录」有效的字母异位词](https://leetcode.cn/problems/valid-anagram/solution/by-carlsun-2-cph7/)
[我自己的草稿](https://flowus.cn/share/22429806-7be9-4834-94e3-2f182d2d87d7
【FlowUs 息流】Untitled (Draft).pdf)
## Test1
# test2
### test3
NBV~0){8C.jpg)
NBV~0){8C.jpg)
https://flowus.cn/share/dcbbbdb5-fac4-4948-9ecb-e3a836e3d081
计划本