MaximumIceCreamBars.cpp

// Source : https://leetcode.com/problems/maximum-ice-cream-bars/
// Author : Hao Chen
// Date   : 2021-04-20

/***************************************************************************************************** 
 *
 * It is a sweltering summer day, and a boy wants to buy some ice cream bars.
 * 
 * At the store, there are n ice cream bars. You are given an array costs of length n, where costs[i] 
 * is the price of the i^th ice cream bar in coins. The boy initially has coins coins to spend, and he 
 * wants to buy as many ice cream bars as possible. 
 * 
 * Return the maximum number of ice cream bars the boy can buy with coins coins.
 * 
 * Note: The boy can buy the ice cream bars in any order.
 * 
 * Example 1:
 * 
 * Input: costs = [1,3,2,4,1], coins = 7
 * Output: 4
 * Explanation: The boy can buy ice cream bars at indices 0,1,2,4 for a total price of 1 + 3 + 2 + 1 = 
 * 7.
 * 
 * Example 2:
 * 
 * Input: costs = [10,6,8,7,7,8], coins = 5
 * Output: 0
 * Explanation: The boy cannot afford any of the ice cream bars.
 * 
 * Example 3:
 * 
 * Input: costs = [1,6,3,1,2,5], coins = 20
 * Output: 6
 * Explanation: The boy can buy all the ice cream bars for a total price of 1 + 6 + 3 + 1 + 2 + 5 = 18.
 * 
 * Constraints:
 * 
 * 	costs.length == n
 * 	1 <= n <= 10^5
 * 	1 <= costs[i] <= 10^5
 * 	1 <= coins <= 10^8
 ******************************************************************************************************/

class Solution {
public:
    int maxIceCream(vector<int>& costs, int coins) {
        sort(costs.begin(), costs.end());
        int cnt = 0;
        for(int i=0; i<costs.size() && costs[i] <= coins; i++) {
            cnt++;
            coins -= costs[i];
        }
        return cnt;
    }
};