Have a bug and need to fix it

function solution(A, K) {

var n = A.length;

for (var i = 0; i < n - 1; i++) {

if (A[i] + 1 < A[i + 1])

return false;

}

if (A[0] != 1 && A[n - 1] != K)

return false;

else

return true;

}