Jump Game 7

#1.BFS
class Solution:
    def canReach(self, s: str, mx: int, my: int) -> bool:
        q=deque()
        far=0
        n=len(s)
        q.append(0)
        while q:
            t=q.popleft()
            if t==n-1:return True
            for x in range(max(t+mx,far+1),min(n,t+my+1)):
                if s[x]!='1':
                    q.append(x)
                    if x==n-1:return True
            far=t+my
        return False
 '''
 Here reach tells how many starting points in the current sliding window helped you to reach current index
2.DP+SLIDING WINDOW'''
class Solution:
    def canReach(self, s: str, mx: int, my: int) -> bool:
        n=len(s)
        dp=[False]*n
        reach=0 #reachable zeroes
        dp[0]=(s[0]=='0')
        for i in range(1,n):
            #at index i window will be from i-maxjumps,i-minjumps
            if i>=mx:#if i-mx is +ve if dp[i-mx] is reachable
                reach = reach+(1 if dp[i-mx] else 0)#why we are adding? Because ith index is added to our sliding window.
            if i>my:
                reach = reach-(1 if dp[i-my-1] else 0) #why we substract because we are leaving i-maxjumps index from our sliding window
            if s[i]=='0' and reach>0:#If current value at index is 0 and if reachable 0s are >0 then we can reach from sliding window (i-maxjumps,i-minjumps)
                dp[i]=True
            else:
                dp[i]=False
        return dp[-1]