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;
}
}