Count all the columns in a matrix which are sorted in descending

Given a matrix mat[][], the task is to count the number of columns that are sorted in descending. 

Examples:

Input: mat[][] = {{1, 3}, {0, 2}} 
Output: 2 First column: 1 > 0 Second column: 3 > 2 Hence, the count is 2 

Input: mat[][] = {{2, 2}, {1, 3}} 
Output: 1

Approach:

Traverse each column one by one and check if the next element ≥ previous element in the same column. If the condition is valid for all the possible elements then increment the count by 1. After all the columns have been traversed, print the count. 

Below is the implementation of the above approach: 

Python3

# Python3 program to count the number of columns
# in a matrix that are sorted in descending

# Function to count the number of columns
# in a matrix that are sorted in descending
def countDescCol(A):

    countOfCol = 0

    for col in zip(*A):
        if all(col[i] >= col[i + 1] for i in range(len(col) - 1)):
            countOfCol += 1

    return countOfCol

# Driver code
A = [[1, 3], [0, 2]]
print(countDescCol(A))

Output

2

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