leetcode notes

发表于2021-11-12更新于2023-08-25字数统计157阅读时长1分

leetcode刷题笔记

二分搜索

二分查找

二分查找，双指针

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class Solution {
    public int search(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        while(left <= right){
            int mid = (left + right )/2;
            if(target == nums[mid]){
                return mid;
            }else if(target < nums[mid]){
                right = mid - 1;
            }else if(target > nums[mid]){
                left = mid + 1;
            }
        }
        retur
    }
}

其他

两数之和

哈希表

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class Solution {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer,Integer> hashMap = new HashMap<>();
        for( int i=0; i < nums.length; i++ ){
            int num = nums[i];
            if(hashMap.containsKey(target-num)){
                return new int[]{i,hashMap.get(target-num)};
            }
            hashMap.put(num,i);
        }
        return new int[]{0};
    }
}