W7_PA1.py

# A Lower triangular matrix is a square matrix (where the number of rows and columns are equal)
# where all the elements above the diagonal are zero.
# For example, the following is an upper triangular matrix with the
# number of rows and columns equal to 3.

# 1 0 0
# 4 5 0
# 7 8 9

# Write a program to convert a square matrix into a lower triangular matrix.

# Input Format:
# The first line of the input contains an integer number n which represents the number of rows and the
# number of columns.
# From the second line, take n lines input with each line containing n integer elements.
# Elements are separated by space.

# Output format:
# Print the elements of the matrix with each row in a new line and each element separated by a space.

# Example 1:
# Input:
# 3
# 1 2 3
# 4 5 6
# 7 8 9

# Output:
# 1 0 0
# 4 5 0
# 7 8 9

# Example 2:
# Input:
# 4
# 12 2  5  6
# 10 11 4  1
# 32 1  4  10
# 1  2  10 9

# Output:
# 12 0 0 0
# 10 11 0 0
# 32 1 4 0
# 1 2 10 9

# Explanation:
# In both the examples, elements which are above the diagonal are zero.

n = int(input())
a = list(map(int, input().split()))


t = 0
t2 = 0
oe = 0
c = n

i = 0
j = 0
while i < n*n: # till 9

    # condition to make zero's after 1'st index and less than n index
    if i != 0 and i < n:
        a[i] = 0

    if i < j:
        if i != 0 and (t2 <= i <= oe):
            a[i] = 0
        j = n + j

    # condition to update data
    if i == c:
        t = n + t
        t2 = t + (n - 1)
        oe = t + n
        c = c + n


    i = i + 1

print(a)


not solved