LCP 18. 早餐组合

小扣在秋日市集选择了一家早餐摊位,一维整型数组 staple 中记录了每种主食的价格,一维整型数组 drinks 中记录了每种饮料的价格。小扣的计划选择一份主食和一款饮料,且花费不超过 x 元。请返回小扣共有多少种购买方案。

注意:答案需要以 1e9 + 7 (1000000007) 为底取模,如:计算初始结果为:1000000008,请返回 1

示例 1:

输入:staple = [10,20,5], drinks = [5,5,2], x = 15

输出:6

解释:小扣有 6 种购买方案,所选主食与所选饮料在数组中对应的下标分别是:
第 1 种方案:staple[0] + drinks[0] = 10 + 5 = 15;
第 2 种方案:staple[0] + drinks[1] = 10 + 5 = 15;
第 3 种方案:staple[0] + drinks[2] = 10 + 2 = 12;
第 4 种方案:staple[2] + drinks[0] = 5 + 5 = 10;
第 5 种方案:staple[2] + drinks[1] = 5 + 5 = 10;
第 6 种方案:staple[2] + drinks[2] = 5 + 2 = 7。

示例 2:

输入:staple = [2,1,1], drinks = [8,9,5,1], x = 9

输出:8

解释:小扣有 8 种购买方案,所选主食与所选饮料在数组中对应的下标分别是:
第 1 种方案:staple[0] + drinks[2] = 2 + 5 = 7;
第 2 种方案:staple[0] + drinks[3] = 2 + 1 = 3;
第 3 种方案:staple[1] + drinks[0] = 1 + 8 = 9;
第 4 种方案:staple[1] + drinks[2] = 1 + 5 = 6;
第 5 种方案:staple[1] + drinks[3] = 1 + 1 = 2;
第 6 种方案:staple[2] + drinks[0] = 1 + 8 = 9;
第 7 种方案:staple[2] + drinks[2] = 1 + 5 = 6;
第 8 种方案:staple[2] + drinks[3] = 1 + 1 = 2;

提示:

    • 1 <= staple.length <= 10^5
    • 1 <= drinks.length <= 10^5
    • 1 <= staple[i],drinks[i] <= 10^5
    • 1 <= x <= 2*10^5

 

 

pass 56 / 65 

 

 

class Solution:
    def breakfastNumber(self, staple: List[int], drinks: List[int], x: int) -> int:
        staple.sort()
        drinks.sort()
        res=0
        for i in range(len(staple)-1,-1,-1):
            if staple[i]+drinks[-1]<=x:
                res+=(i+1)*len(drinks)
                break
            if staple[i]>=x:
                continue
            for j in range(len(drinks)-1,-1,-1):
                if staple[i]+drinks[j]<=x:
                    res+=j+1
                    break
        return int(res%(1000000007))

 

ac

class Solution:
    def breakfastNumber(self, staple: List[int], drinks: List[int], x: int) -> int:
        staple.sort()
        drinks.sort()
        res=0
        i,j=0,len(drinks)-1
        while i<len(staple) and j>=0:
            if staple[i]+drinks[j]>x:
                j-=1
            else:
                res+=j+1
                i+=1
        return int(res%(1000000007))

 

上一篇:模拟赛 drinks 题解


下一篇:Python还能判断出早餐组合购买方案?吃早餐再也不愁不知道吃什么了