题目:

There are N children standing in a line. Each child is assigned a rating value.

You are giving candies to these children subjected to the following requirements:

  • Each child must have at least one candy.
  • Children with a higher rating get more candies than their neighbors.

What is the minimum candies you must give?

思路:

首先初始化每个人一个糖果,然后这个算法需要遍历两遍,第一遍从左向右遍历,如果右边的小盆友的等级高,等加一个糖果,这样保证了一个方向上高等级的糖果多。然后再从右向左遍历一遍,如果相邻两个左边的等级高,而左边的糖果又少的话,则左边糖果数为右边糖果数加一。最后再把所有小盆友的糖果数都加起来返回即可。

代码:

public class Solution {
public int candy(int[] ratings) {
int[] nums = new int[ratings.length];
for (int i=0; i<ratings.length; i++) {
nums[i] = 1;
}
for (int i=0; i<ratings.length - 1; i++) {
if (ratings[i+1] > ratings[i]) {
nums[i+1] = nums[i] + 1;
}
} for (int i=ratings.length - 1; i>0; i--) {
if (ratings[i-1] > ratings[i]) {
nums[i-1] = Math.max(nums[i] + 1, nums[i - 1]);
}
} int res = 0;
for (int i=0; i<ratings.length; i++) {
res += nums[i];
} return res;
}
}

  

05-15 18:16