视频讲解

视频链接：https://www.bilibili.com/video/BV1uz4y1U71X/
左右各遍历一次。

import java.util.*;


public class Solution {
    /**
     * pick candy
     * @param arr int整型一维数组 the array
     * @return int整型
     */
    public int candy (int[] arr) {
        int res[] = new int[arr.length];
        Arrays.fill(res, 1);
        int count = 0;

        for (int i = 1; i < arr.length; i++){
            if (arr[i] > arr[i - 1]){
                res[i] = res[i - 1] + 1;
            }
        }

        for (int i = arr.length - 1; i > 0; i--){
            if (arr[i - 1] > arr[i]){
                res[i - 1] = Math.max(res[i - 1], res[i] + 1);
            }
        }

        for (int i: res){
            count += i;
        }

        return count;
    }
}