You are given a 0-indexed binary string s and two integers minJump and maxJump. In the beginning, you are standing at index 0, which is equal to '0'. You can move from index i to index j if the following conditions are fulfilled:
i + minJump <= j <= min(i + maxJump, s.length - 1), ands[j] == '0'.Return true if you can reach index s.length - 1 in s, or false otherwise.
Example 1:
Input: s = "011010", minJump = 2, maxJump = 3 Output: true Explanation: In the first step, move from index 0 to index 3. In the second step, move from index 3 to index 5.
Example 2:
Input: s = "01101110", minJump = 2, maxJump = 3 Output: false
Constraints:
2 <= s.length <= 105s[i] is either '0' or '1'.s[0] == '0'1 <= minJump <= maxJump < s.lengthA BFS approach involves using a queue to explore all possible indices starting from index 0. Each index is checked for the conditions, and if any index meets the criteria, it is added to the queue for further exploration. This ensures all reachable indices are visited.
This solution uses a boolean array to keep track of reachable indices. Starting from index 0, it explores indices within the allowed jump range. If an index is reachable, it is marked in the boolean array. This array is then used to explore further indices until all reachable indices are processed. The result is determined by whether the last index can be reached.
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Time Complexity: O(n) - where n is the length of the string s. Each index is processed once.
Space Complexity: O(n) - for the boolean array to track reachable indices.
To further optimize, a sliding window or prefix sum method is used to reduce the number of operations needed by focusing on maintaining a window of reachable indices, eliminating inner loops for checking reachable segments, and accumulating results incrementally.
This C solution utilizes a sliding window or prefix sum approach to maintain a count of reachable indices. By checking indices directly within the window constraint, it adds or deducts from the `reached` count, optimizing previous brute-force reach checks per index.
C++
Java
Python
C#
JavaScript
Time Complexity: O(n)
Space Complexity: O(n)
| Approach | Complexity |
|---|---|
| Breadth-First Search (BFS) Approach | Time Complexity: O(n) - where n is the length of the string s. Each index is processed once. |
| Sliding Window Optimization | Time Complexity: O(n) |
Jump Game VII - Leetcode 1871 - Python • NeetCode • 16,034 views views
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