Find Maxmium number count in list and nth number

1、Find Max number in list

def main():
    a = [1,4,3]
    max_val = -1
    for i in range(0,len(a)):
        if a[i] > max_val:
            max_val = a[i]
    return max_val

if __name__ == "__main__":
    print(main())

• max_val = -1

for i in range(0,len(a)):
        if a[i] > max_val:
            max_val = a[i]

2、Find Max count in list

def main():
    a = [1, 3, 4, 3, 4, 1, 3]
    time_tmp = 0
    time_max = 0 
    result={}

    for i in range(0,len(a)):
        for j in range(0,len(a)):
            if a[i] == a[j]:
                time_tmp += 1
        # result[a[i]] = time_tmp

    # return result

        if time_tmp > time_max:
            time_max = time_tmp
            val_max = a[i]

    return val_max

if __name__ == "__main__":
    print(main())

output:
3

2、Find Max count variable in list with dictionary

a = [1, 2, 3, 4, 5, 5, 5, 6]

d = {}    # a[i]为key, count 为 value
result = []

for i in range(0,len(a)):
    if a[i] in d.keys():
        d[a[i]] = d.get(a[i])+1
    else:
        d[a[i]] = 1

    # val_max = -1
    # time_max = 0

for count in d.values():
    result.append(count)

# return result
print(max(result))

output:
3

3、 Find the most n repeated word in a string

N largest values in dictionary

from collections import Counter

def getNthFrequency(str, n):
    array = str.split(' ')
    res_array = []
    i = 1
    # return array
    res_dict = dict(Counter(array))
    # return result
    while i <= n:
        maximum_key = max(res_dict, key=res_dict.get)
        res_array.append(maximum_key)
        res_dict.pop(maximum_key)
        i += 1

    return res_array


if __name__ == '__main__':
    str = "In this program, to use Counter, we have to import it from the collections class in our program. Since Counter works for hashable objects they are accessed using a key. We can get the Key using the get method."
    print(getNthFrequency(str,2))

maximum_key = max(res_dict, key=res_dict.get)

['the', 'to']

from collections import Counter
from heapq import nlargest


def getNthFrequency(str, N):
    array = str.split(' ')
    res_array = []
    i = 1
    # return array
    res_dict = dict(Counter(array))
    # N largest values in dictionary
    # Using nlargest
    res = nlargest(N, res_dict, key = res_dict.get)
    return res 

if __name__ == '__main__':
    str = "In this program, to use Counter, we have to import it from the collections class in our program. Since Counter works for hashable objects they are accessed using a key. We can get the Key using the get method."
    print(getNthFrequency(str,3))

['the', 'to', 'using']

4、Find Nth number in list

在一个有序数组中，查找出第一个大于 9 的数字，假设一定存在。例如，arr = { -1, 3, 3, 7, 10, 14, 14 };

def main():
    targetNumb = 9
    arr = [ -1, 3, 3, 7, 10, 14, 14 ]
    middle = 0
    low = 0
    high = len(arr) - 1

    while low <= high:
        middle = round((high + low)/2)
        if arr[middle] > targetNumb and (middle == 0 or arr[middle-1] <= targetNumb):
            print(f"The first number bigger than {targetNumb} which is {arr[middle]}")
            break
        elif arr[middle] > targetNumb:
            # 说明该数在low~middle之间
            high = middle - 1
        else:
            #  说明该数在middle~high之间
            low = middle + 1


if __name__ == "__main__":
    main()

The first number bigger than 9 which is 10