[LeetCode Exercise] [Difficulty] 135. Distribute candies
135. Distribute candies
Algorithm idea: array, greedy
topic:
java code
class Solution {
public int candy(int[] ratings) {
//从前向后,从后向前,都要满足关系,进行两次遍历
if(ratings == null || ratings.length == 0){
return 0;
}
int[] nums = new int[ratings.length];//记录每一位孩子得到的糖果数
nums[0] = 1;
//先正序遍历，如果后一位比前一位高分，就给比前一位多1的糖果，否则给1
for(int i = 1; i < ratings.length; i++){
if(ratings[i] > ratings[i-1]){
nums[i] = nums[i-1] + 1;
}else {
nums[i] = 1;
}
}
//在倒叙遍历，如果前一位比后一位高分并且得到的糖果小于或等于后一位，就给前一位孩子比后一位孩子多一个糖果
for(int i = ratings.length -2 ; i >= 0; i--){
if(ratings[i] > ratings[i+1] && nums[i] <= nums[i+1]){
nums[i] = nums[i+1] +1;
}
}
int count = 0;
for(int i : nums){
count +=i;
}
return count;
}
}