[HackerRank] Plus Minus

HackerRank - 1 Week Preparation Kit - Day1 - Plus Minus

Plus Minus

Given an array of integers, calculate the ratios of its elements that are positive, negative, and zero. Print the decimal value of each fraction on a new line with 6 places after the decimal.

Note: This challenge introduces precision problems. The test cases are scaled to six decimal places, though answers with absolute error of up to 0.0001 are acceptable.

 

Example

arr = [1, 1, 0, -1, -1]

 

There are n=5 elements, two positive, two negative and one zero. Their ratios are 2/5 = 0.400000, 2/5 = 0.400000, and 1/5 = 0.200000. Results are printed as:

0.400000
0.400000
0.200000

 

Function Description

Complete the plusMinus function in the editor below.

plusMinus has the following parameter(s):

• int arr[n]: an array of integers

Print
Print the ratios of positive, negative and zero values in the array. Each value should be printed on a separate line with 6 digits after the decimal. The function should not return a value.

 

Input Format

The first line contains an integer, n, the size of the array.
The second line contains n space-separated integers that describe  arr[n].

 

Constraints

0 < n <= 100
-100 <= arr[i] <= 100

 

Output Format

Print the following 3  lines, each to 6  decimals:

1. proportion of positive values
2. proportion of negative values
3. proportion of zeros

Sample Input

STDIN           Function
-----           --------
6               arr[] size n = 6
-4 3 -9 0 4 1   arr = [-4, 3, -9, 0, 4, 1]

Sample Output

0.500000
0.333333
0.166667

 

Explanation

There are 3 positive numbers, 2 negative numbers, and 1 zero in the array.
The proportions of occurrence are positive: 3/6 = 0.500000, negative: 2/6 = 0.333333  and zeros: 1/6 = 0,166667.

---

import math
import os
import random
import re
import sys


#
# Complete the 'plusMinus' function below.
#
# The function accepts INTEGER_ARRAY arr as parameter.
#

def plusMinus(arr):
    # Write your code here
    pos = 0
    nag = 0
    zero = 0

    for i in arr:
        if i > 0:
            pos += 1
        elif i < 0:
            nag += 1
        else:
            zero += 1
    print("{: .6f}\n{: .6f}\n{: 6f}".format(pos / len(arr), nag / len(arr), zero / len(arr)))


if __name__ == '__main__':
    n = int(input().strip())
    arr = list(map(int, input().rstrip().split()))

    plusMinus(arr)

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1일차라 그런지 생각보다 쉽다. 굿