leetcode 475. Heaters

1.题目

Winter is coming! Your first job during the contest is to design a standard heater with fixed warm radius to warm all the houses.

Now, you are given positions of houses and heaters on a horizontal line, find out minimum radius of heaters so that all houses could be covered by those heaters.

So, your input will be the positions of houses and heaters seperately, and your expected output will be the minimum radius standard of heaters.

Note:
Numbers of houses and heaters you are given are non-negative and will not exceed 25000.
Positions of houses and heaters you are given are non-negative and will not exceed 10^9.
As long as a house is in the heaters’ warm radius range, it can be warmed.
All the heaters follow your radius standard and the warm radius will the same.
翻译：用一个数组表示房间的位置，一个数组表示暖气的位置。求最小的暖气保暖半径，使得所有房间都能保暖。
Example 1:
Input: [1,2,3],[2]
Output: 1
Explanation: The only heater was placed in the position 2, and if we use the radius 1 standard, then all the houses can be warmed.
Example 2:
Input: [1,2,3,4],[1,4]
Output: 1
Explanation: The two heater was placed in the position 1 and 4. We need to use radius 1 standard, then all the houses can be warmed.

2.分析

遍历一遍房间数组，对于每个房间，找到离他最近的暖气，求距离。 依次比较这个距离求最大值即可。

3.代码

class Solution {public:    int findRadius(vector<int>& houses, vector<int>& heaters) {        int minRadius = 0;        int j = 0;        sort(houses.begin(), houses.end());        sort(heaters.begin(), heaters.end());        for (int h : houses) {            while (j < heaters.size()-1 && (abs(heaters[j] - h) >= abs(heaters[j + 1] - h)))                ++j;            minRadius = minRadius > abs(heaters[j] - h) ? minRadius : abs(heaters[j] - h);        }        return minRadius;    }};