879.profitable schemes

Description

There are G people in a gang, and a list of various crimes they could commit.

The i-th crime generates a profit[i] and requires group[i] gang members to participate.

If a gang member participates in one crime, that member can’t participate in another crime.

Let’s call a profitable scheme any subset of these crimes that generates at least P profit, and the total number of gang members participating in that subset of crimes is at most G.

How many schemes can be chosen? Since the answer may be very large, return it modulo 10^9 + 7.

题目链接:https://leetcode.com/problems/profitable-schemes/

Difficulty: hard

Example 1:

Input: G = 5, P = 3, group = [2,2], profit = [2,3]
Output: 2
Explanation: 
To make a profit of at least 3, the gang could either commit crimes 0 and 1, or just crime 1.
In total, there are 2 schemes.

Example 2:

Input: G = 10, P = 5, group = [2,3,5], profit = [6,7,8]
Output: 7
Explanation: 
To make a profit of at least 5, the gang could commit any crimes, as long as they commit one.
There are 7 possible schemes: (0), (1), (2), (0,1), (0,2), (1,2), and (0,1,2).

Note:

  • 1 <= G <= 100
  • 0 <= P <= 100
  • 1 <= group[i] <= 100
  • 0 <= profit[i] <= 100
  • 1 <= group.length = profit.length <= 100

分析

  1. 反面教材->递归,updating

参考代码

class Solution:
def profitableSchemes(self, G, P, group, profit):
    length=len(group)
    target=0
    def _inter(index,sumG,sumP):
        if(sumG+group[index]<=G and sumP+profit[index]>=P):
            nonlocal target
            target+=1
        if(index+1<length):
            _inter(index+1,sumG,sumP)
            if(sumG+group[index]<=G):
                _inter(index+1,sumG+group[index],sumP+profit[index])
    _inter(0,0,0)
    return target