Is This a Long Challenge | CodeChef

help
1

Can anybody help me with this, I’m getting time limit exceeded error always when I try to solve. I’m an amateur btw XD.

here’s my code in python 3.6

try:
t = int(input())
except:
t = 0
MOD = 1000000007
for i in range(t):
n = int(input())
s = input()
s_list = list(s)
q = int(input())
queries = []

for j in range(q):
    queries.append(list(input().rstrip().split()))
    

for j in queries:
    start  = int(j[1]) - 1 
    end = int(j[2]) - 1
    k = start
    if j[0] == '1':
        while k <= end:
            s_list[k] = j[3]
            k+=1
    else:
        while k <= end:
            temp_p = int(j[3])
            temp_q = int(j[4])
            if s_list[k] == 'A':
                # temp_p = int(j[3])
                # temp_q = int(j[4])
                j[3] = (temp_p%MOD - temp_q%MOD)%MOD
                j[4] = (temp_p%MOD + temp_q%MOD)%MOD
            else:
                # temp_p = int(j[3])
                # temp_q = int(j[4])
                j[3] = (temp_p%MOD + temp_q%MOD)%MOD
                j[4] = (temp_q%MOD - temp_p%MOD)%MOD
                
            k+=1
            
        print(j[3], j[4])
2

Brute force is not going to work, You need to use a segment tree of matrices with lazy propogations. I would recommend you to try easier problems first.
Or if you are confident, I would advise you to read up on segment trees.

3

Oh, Thank you! I’ll try easier problems first and also read up on segment trees.

4

BTW can you guide me how can go about Data structures and algorithms? or sites i can refer and study

5

https://cp-algorithms.com/

6

It can be done also by simple array iteration by only observing the pattern.

7

I remember trying, I saw some figment of a pattern, but the updating causes problems.

8

Thanks a lot, it quite helps me in learning everything required for Competitive programming.