[LeetCode]881. Boats to Save People 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/boats-to-save-people/description/ 题目描述: The i-th person has weight people[i], and each boat can carry a maximu…

The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those people is at most limit. Return the minimum number of boats to carry…

The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those people is at most limit. Return the minimum number of boats to carry…

The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those people is at most limit. Return the minimum number of boats to carry…

原题链接在这里:https://leetcode.com/problems/boats-to-save-people/ 题目: The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those peop…

[题目] The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those people is at most limit. Return the minimum number of boats to…

The i-th person has weight people[i], and each boat can carry a maximum weight of limit. Each boat carries at most 2 people at the same time, provided the sum of the weight of those people is at most limit. Return the minimum number of boats to carry…

题目如下: 解题思路:本题可以采用贪心算法,因为每条船最多只能坐两人,所以在选定其中一人的情况下,再选择第二个人使得两人的体重最接近limit.考虑到人的总数最大是50000,而每个人的体重最大是30000,因此会有很多人体重一样.这样可以用一个集合set保存体重,再用字典保存每个体重对应的人的数量,可以减少运算量.最后对set进行升序排序,再用双指针的方法,用low指针指向set头部,high指针指向set尾部,分别比较set[low]和set[high]的值,有如下情况: a. set[lo…

双指针基础 双指针(Two Pointers)是面对数组.链表结构的一种处理技巧.这里“指针”是泛指,不但包括通常意义上的指针,还包括索引.迭代器等可用于遍历的游标. 同方向指针 设定两个指针.从头往尾(或从尾到头)遍历,我称之为同方向指针,第一个指针用于遍历,第二个指针满足一定条件下移动.例如 LeetCode题目 283. Move Zeroes: // 283. Move Zeroes void moveZeroes(vector<int>& nums) { ; ;j<nu…

贪心基础 贪心(Greedy)常用于解决最优问题,以期通过某种策略获得一系列局部最优解.从而求得整体最优解. 贪心从局部最优角度考虑,只适用于具备无后效性的问题,即某个状态以前的过程不影响以后的状态.紧接下来的状态仅与当前状态有关.和分治.动态规划一样,贪心是一种思路,不是解决某类问题的具体方法. 应用贪心的关键,是甄别问题是否具备无后效性.找到获得局部最优的策略.有的问题比较浅显,例如一道找零钱的题目 LeetCode 860. Lemonade Change: // 860. Lemonad…