#include <vector>

#include <numeric>

#include <algorithm>

int candies(std::vector<int>& ratings) {

int n = ratings.size();

// Ensure each child starts with 1 candy.

std::vector<int> candies(n, 1);

// First pass: for each child, ensure the child has more candies

// than their left-side neighbor if the current child's rating is

// higher.

for (int i = 1; i < n; i++) {

if (ratings[i] > ratings[i - 1]) {

candies[i] = candies[i - 1] + 1;

}

}

// Second pass: for each child, ensure the child has more candies

// than their right-side neighbor if the current child's rating is

// higher.

for (int i = n - 2; i >= 0; i--) {

if (ratings[i] > ratings[i + 1]) {

// If the current child already has more candies than their

// right-side neighbor, keep the higher amount.

candies[i] = std::max(candies[i], candies[i + 1] + 1);

}

}

return std::accumulate(candies.begin(), candies.end(), 0);

}