jump game sol 1.java

public class Solution {
    public boolean canJump(int[] A) {
        if (A == null)
            return false;
        int len = A.length;
        if (len == 0)
            return false;
        int rightBound = A[0];
        int i = 0;
        while (i <= rightBound) {
            if (i + A[i] > rightBound)
                rightBound = i + A[i];
            if (rightBound >= len - 1)
                return true;
            i++;
        }
        return false;
    }
}