Diagonals with same characters - Python - python-3.x

Question

The program must accept a character matrix of size RxC as the input. The program must print the number of diagonals that parallel to the top-left to bottom-right diagonal and having the same characters in the matrix.
def lower_diagonals(row,matrix):
# a list to store the lower diagonals
# which are || to top left to bottom right
d=[]
# Iterating from the second row till the last row
for i in range(1,row):
nop,dummy = [],0
for j in range(i,row):
try:
nop.append(matrix[j][dummy])
except:
break
dummy+=1
d.append(nop)
return d
def upper_diagonals(col,matrix):
# a list to store the lower diagonals
# which are || to top left to bottom right
d=[]
# Iterating from 1st column till the last column
for i in range(1,col):
dum , nop = i,[]
# Iterating till the last before row
for j in range(row-1):
try:
nop.append(matrix[j][dum])
except:
break
dum+=1
d.append(nop)
return d
def diagonals(matrix,row,col):
return lower_diagonals(row,matrix) + upper_diagonals(col,matrix)
row,col = map(int,input().input().split())
matrix =[input().strip().split(' ') for i in range(row)]
new_matrix = diagonals(matrix,row,col)
t=0
for i in new_matrix:
if len(list(set(i))) == 1 : t+=1
print(t)
Example :
Input :
4 4
u m o a
h n a o
y h r w
b n h e
Output:
4
Input :
5 7
G a # z U p 3
e G b # n U p
a e G m # e U
L l e g k # t
j L a e G s #
Output:
6
My code works perfect for all the above mentioned cases but it fails for the below case
Input :
2 100
b h D k 2 D 9 I e Q # * B 5 H Z r q u n P C 4 a e K l 2 E p 6 R V v 0 d 8 x C F P M F C e m K H O y # 0 I T r P 8 P N 9 Z 7 S J J P c L g x X f 5 1 o i Y V Y G Y 9 A E O 2 r 2 # S 8 z D 6 a q r i k r
V o 4 T M m z p 6 G H D Y a 6 t O 7 # w y t 2 m A 1 a + 0 p t P D z 7 V N T x + I t 4 x x y 1 Q G M t M 0 v d G e u 4 b 8 m D # I v D i T 1 u L f e 1 Y E Y q Y c A 8 P 2 q 2 A 8 y b u E 3 c 1 s M n X
Expected Output:
9
My Output:
100
Can anyone help me in structuring the logic for this case Thanks in advance
Note :
2<=R,C<=100
Time limit : 500ms

Answer 1

I think i probably found a logic for my problem
r,c = map(int,input().strip().split())
mat = []
for i in range(r):
l = list(map(str,input().strip().split()))
mat.append(l[::-1])
count = 0
for i in range(r+c-1):
l = []
for row in range(r):
for col in range(c):
if row+col == i:
l.append(mat[row][col])
l = list(set(l))
if len(l) == 1:
count+=1
print(count)