|
| 1 | +#!/usr/bin/python3 |
| 2 | +""" |
| 3 | +There are 2N people a company is planning to interview. The cost of flying the |
| 4 | +i-th person to city A is costs[i][0], and the cost of flying the i-th person to |
| 5 | +city B is costs[i][1]. |
| 6 | +
|
| 7 | +Return the minimum cost to fly every person to a city such that exactly N people |
| 8 | +arrive in each city. |
| 9 | +
|
| 10 | +
|
| 11 | +
|
| 12 | +Example 1: |
| 13 | +
|
| 14 | +Input: [[10,20],[30,200],[400,50],[30,20]] |
| 15 | +Output: 110 |
| 16 | +Explanation: |
| 17 | +The first person goes to city A for a cost of 10. |
| 18 | +The second person goes to city A for a cost of 30. |
| 19 | +The third person goes to city B for a cost of 50. |
| 20 | +The fourth person goes to city B for a cost of 20. |
| 21 | +
|
| 22 | +The total minimum cost is 10 + 30 + 50 + 20 = 110 to have half the people |
| 23 | +interviewing in each city. |
| 24 | +
|
| 25 | +Note: |
| 26 | +
|
| 27 | +1 <= costs.length <= 100 |
| 28 | +It is guaranteed that costs.length is even. |
| 29 | +1 <= costs[i][0], costs[i][1] <= 1000 |
| 30 | +""" |
| 31 | + |
| 32 | + |
| 33 | +classSolution: |
| 34 | +deftwoCitySchedCost(self,costs:List[List[int]])->int: |
| 35 | +""" |
| 36 | + sort by city A and greedy? [30, 20]? |
| 37 | + sort by total? |
| 38 | + sort by diff - either choose A or B, the difference matters |
| 39 | +
|
| 40 | + a - b: incremental cost of flying A instead of B |
| 41 | + """ |
| 42 | +A= [(a-b,a,b)fora,bincosts] |
| 43 | +A.sort() |
| 44 | +ret=0 |
| 45 | +remain=len(A)//2 |
| 46 | +for_,a,binA: |
| 47 | +ifremain>0: |
| 48 | +ret+=a |
| 49 | +remain-=1 |
| 50 | +else: |
| 51 | +ret+=b |
| 52 | + |
| 53 | +returnret |
| 54 | + |
| 55 | +deftwoCitySchedCost_error(self,costs:List[List[int]])->int: |
| 56 | +""" |
| 57 | + sort by city A and greedy? [30, 20]? |
| 58 | + sort by total? |
| 59 | + sort by diff - either choose A or B, the difference matters |
| 60 | +
|
| 61 | + Error in the abs of difference |
| 62 | + """ |
| 63 | +A= [(abs(a-b),a,b)fora,bincosts] |
| 64 | +A.sort(reverse=True) |
| 65 | +ret=0 |
| 66 | +remain=len(A)//2 |
| 67 | +for_,a,binA: |
| 68 | +ifa>b: |
| 69 | +ret+=b |
| 70 | +elifremain>0: |
| 71 | +ret+=a |
| 72 | +remain-=1 |
| 73 | +else: |
| 74 | +ret+=b |
| 75 | + |
| 76 | +returnret |