[python] codeSignal 문제풀이 (7~8)

7. Given a sequence of integers as an array, determine whether it is possible to obtain a strictly increasing sequence by removing no more than one element from the array.

Note: sequence a0, a1, ..., an is considered to be a strictly increasing if a0 < a1 < ... < an. Sequence containing only one element is also considered to be strictly increasing.

 

어떤 수들이 나열되어 있을 때, 그 수열 중에 한 숫자만 빼서 증가 수열이 될 수 있는가?

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Example)

 

For sequence = [1, 3, 2, 1], the output should be almostIncreasingSequence(sequence) = false.

There is no one element in this array that can be removed in order to get a strictly increasing sequence.

 

For sequence = [1, 3, 2], the output should be almostIncreasingSequence(sequence) = true.

You can remove 3 from the array to get the strictly increasing sequence [1, 2]. Alternately, you can remove 2 to get the strictly increasing sequence [1, 3].

def almostIncreasingSequence(sequence):
    droppped = False
    last = prev = min(sequence) - 1
    for elm in sequence:
        if elm <= last:
            if droppped:
                return False
            else:
                droppped = True
            if elm <= prev:
                prev = last
            elif elm >= prev:
                prev = last = elm
        else:
            prev, last = last, elm
    return True

=> Best Answer / 풀지 못하여 다음 번에 재도전하기로!

 

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8. After becoming famous, the CodeBots decided to move into a new building together. Each of the rooms has a different cost, and some of them are free, but there's a rumour that all the free rooms are haunted! Since the CodeBots are quite superstitious, they refuse to stay in any of the free rooms, or any of the rooms below any of the free rooms.

Given matrix, a rectangular matrix of integers, where each value represents the cost of the room, your task is to return the total sum of all rooms that are suitable for the CodeBots (ie: add up all the values that don't appear below a 0).

 

Example)

 

For matrix = [[0, 1, 1, 2], [0, 5, 0, 0], [2, 0, 3, 3]] the output should be matrixElementsSum(matrix) = 9.

There are several haunted rooms, so we'll disregard them as well as any rooms beneath them.

Thus, the answer is 1 + 5 + 1 + 2 = 9.

 

For matrix = [[1, 1, 1, 0], [0, 5, 0, 1], [2, 1, 3, 10]] the output should be matrixElementsSum(matrix) = 9.

Note that the free room in the final column makes the full column unsuitable for bots (not just the room directly beneath it). Thus, the answer is 1 + 1 + 1 + 5 + 1 = 9.

 

def matrixElementsSum(matrix):
    for i in range(len(matrix)):
        for j in range(len(matrix[i])):
            if matrix[i][j] == 0:
                for k in range(i + 1, len(matrix)):
                    matrix[k][j] = 0
    return sum(sum(x) for x in matrix)

 

# BestSolution

 

def matrixElementsSum(m):
    r = len(m)
    c = len(m[0])
    total=0
    for j in range(c):
        for i in range(r):
            if m[i][j]!=0:
                total+=m[i][j]
            else:
                break
    return total

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