Greedy.
Note that if we can reach position k, we can reach all positions from 0 to k.
public class Solution {
public boolean canJump(int[] nums) {
int maxIdx = 0;
for (int i = 0; i <= nums.length; ++i) {
if (i > maxIdx) return false;
maxIdx = Math.max(i + nums[i], maxIdx);
if (maxIdx >= nums.length - 1) return true;
}
return false;
}
}