LeetCode 55. Jump Game

这道题可以用贪心算法也可以用动态规划。老师说虽然动态规划的解法时间复杂度更高，但更具有普遍性。代码如下：

class Solution {
    public boolean canJump(int[] nums) {
        int n = nums.length;
        if(n == 1){
            return true;
        }
        boolean[] dp = new boolean[n];
        dp[n - 1] = true;
        for(int i = n - 2; i >= 0; i--){
            // Check whether the reachable positions can jump to the end
            for(int j = i + 1; j <= i + nums[i] && j < n; j++){
                if(dp[j]){
                    dp[i] = true;
                    break;
                }
            }
        }
        return dp[0];
    }
}

---

class Solution {
    public boolean canJump(int[] nums) {
        int n = nums.length;
        int lastPos = n - 1;
        for(int i = n - 2; i >= 0; i--){
            if(i + nums[i] >= lastPos){
                lastPos = i;
            }
        }
        return lastPos == 0;
    }
}