zoukankan      html  css  js  c++  java
  • LeetCode(一)

    Q&A ONE

    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, and you may not use the same element twice.

    Example:
    Given nums = [2, 7, 11, 15], target = 9,

    Because nums[0] + nums[1] = 2 + 7 = 9,
    return [0, 1].

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

    Q&A TWO

    Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
    The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.
    You may assume that each input would have exactly one solution and you may not use the same element twice.
    Input: numbers={2, 7, 11, 15}, target=9
    Output: index1=1, index2=2

    考虑到事件复杂度第一种方法已经变得不可行。由于已经排好序,所以采用一种类似于快排的思路:

    从最大最小开始找(即数组的两端向中间逼进)

    • 加起来太大则大的一端往中间移动
    • 加起来太小则小的一端往中间移动
    public int[] twoSum(int[] num, int target) {
            int[] indice = new int[2];
            if (num == null || num.length < 2) return indice;
            int left = 0, right = num.length - 1;
            while (left < right) {
                int v = num[left] + num[right];
                if (v == target) {
                    indice[0] = left + 1;
                    indice[1] = right + 1;
                    break;
                } else if (v > target) {
                    right--;
                } else {
                    left++;
                }
            }
            return indice;
        }

     

  • 相关阅读:
    vim中自动添加文件的作者、时间信息、版本等
    linux shell ipaddress
    java ant学习
    ganglia rpm安装
    深入分析 Java 中的中文编码问题
    javaIO调优
    超强的vim设置
    linux中core文件的生成和配置
    C和C++ 语言动态内存分配
    Linux的常用命令
  • 原文地址:https://www.cnblogs.com/rekent/p/7217959.html
Copyright © 2011-2022 走看看