• Time:O(n)
• Space:O(n)

## C++

``````class Solution {
public:
int candy(vector<int>& ratings) {
const int n = ratings.size();
int ans = 0;
vector<int> l(n, 1);
vector<int> r(n, 1);

for (int i = 1; i < n; ++i)
if (ratings[i] > ratings[i - 1])
l[i] = l[i - 1] + 1;

for (int i = n - 2; i >= 0; --i)
if (ratings[i] > ratings[i + 1])
r[i] = r[i + 1] + 1;

for (int i = 0; i < n; ++i)
ans += max(l[i], r[i]);

return ans;
}
};
``````

## JAVA

``````class Solution {
public int candy(int[] ratings) {
final int n = ratings.length;

int ans = 0;
int[] l = new int[n];
int[] r = new int[n];
Arrays.fill(l, 1);
Arrays.fill(r, 1);

for (int i = 1; i < n; ++i)
if (ratings[i] > ratings[i - 1])
l[i] = l[i - 1] + 1;

for (int i = n - 2; i >= 0; --i)
if (ratings[i] > ratings[i + 1])
r[i] = r[i + 1] + 1;

for (int i = 0; i < n; ++i)
ans += Math.max(l[i], r[i]);

return ans;
}
}
``````

## Python

``````class Solution:
def candy(self, ratings: List[int]) -> int:
n = len(ratings)

ans = 0
l = [1] * n
r = [1] * n

for i in range(1, n):
if ratings[i] > ratings[i - 1]:
l[i] = l[i - 1] + 1

for i in range(n - 2, -1, -1):
if ratings[i] > ratings[i + 1]:
r[i] = r[i + 1] + 1

for a, b in zip(l, r):
ans += max(a, b)

return ans
``````