Jump Game

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Determine if you are able to reach the last index.

For example:
A = [2,3,1,1,4], return true.

A = [3,2,1,0,4], return false.


Analysis: DP. See the comments. 

public class Solution {
    public boolean canJump(int[] A) {
        if(A.length==0 || A.length==1) return true;     // edge case
        
        int maxJumpIndex = A[0];    // the maximum index that can be reached from current position
        for(int i=1; i<A.length; i++) {
            // if current position can be reached, update maxJumpIndex
            // maxJumpIndex = max{ largest postions from previous, largest positions from current }
            if(maxJumpIndex>=i) maxJumpIndex=Math.max(A[i]+i, maxJumpIndex);
            else return false;      // current position cannot be reached from the previous ones
        }
        return true;
    }
}

發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章