The answer is obtained by swapping the \(K\) 1-block and the 0-block right before that.

Thus, the problem can be solved by the following algorithm:

1. Split the string by the boundaries of 0 and 1.
2. Swap the \(K\)-th 1-block and the previous block.
3. Concatenate the string.

Sample input 1：

010011100011001
↓ split
0 1 00 111 000 11 00 1
↓ swap
0 1 00 111 11 000 00 1
↓ join
010011111000001

Sample code (Python)

N,K = map(int,input().split())
S = input()

# split
idx = [0] + [i for i in range(1,N) if S[i-1]!=S[i]] + [N]
splited_S = [S[idx[i]:idx[i+1]] for i in range(len(idx)-1)]

# swap
if S[0] == '0':
  kth_1_idx = 2*K-1
else:
  kth_1_idx = 2*K-2

splited_S[kth_1_idx-1], splited_S[kth_1_idx] = splited_S[kth_1_idx], splited_S[kth_1_idx-1]

# join
T = "".join(splited_S)

print(T)