KLXOR-runtime error

editorial
,
1

for a in range(int(input())):
n,k=map(int,input().split())
s=input()
lst1=[]
for i in range(((len(s)-k)+1)):
s1=s[i:k+i]
lst1.append(s1)
x=0
for j in range(len(lst1)):
x=x^int(lst1[j])
x=str(x)
print(x.count(“1”))
I am getting runtime error can anyone tell me whyKLXOR - Editorial

2

Hi @ayushgiri_190

I think you’ll find this video to be helpful,
KLXOR | AGAIN XOR PROBLEM | December CodeDrive 2021 | Problem Solutions | CodeChef

Here’s a python code

T = int(input())

for _ in range(T):

    n,k = input().split()
    s = input()

    n = int(n)
    k = int(k)

    ans = 0 
    c = 0

    for i in range(0,n-k):

        if s[i] == '1':
            c += 1 

    for j in range(0,k):

        if s[n-k+j] == '1':
            c += 1 

        if c%2 != 0:
            ans += 1

        if s[j] == '1':
            c -= 1 

    print(ans)

a better approach

def func():
    n, k = map(int, input().split())
    c = 0
    ans = 0
    s = input()
    for i in range(n-k+1):
        if s[i] == '1':
            c += 1
    #print(n-k, end = " ")
    #print(c)
    if c%2 == 1:
        ans += 1
    for i in range(n-k+1, n):
        if s[i-n+k-1] == '1':
            c -= 1
        if s[i] == '1':
            c += 1
        if c%2 == 1:
            ans += 1
        #print(i, end = " ")
        #print(c)
    print(ans)

t = int(input())
for i in range(t):
    func()