题目：

题解：

class Solution {public boolean canCross(int[] stones) {int n = stones.length;boolean[][] dp = new boolean[n][n];dp[0][0] = true;for (int i = 1; i < n; ++i) {if (stones[i] - stones[i - 1] > i) {return false;}}for (int i = 1; i < n; ++i) {for (int j = i - 1; j >= 0; --j) {int k = stones[i] - stones[j];if (k > j + 1) {break;}dp[i][k] = dp[j][k - 1] || dp[j][k] || dp[j][k + 1];if (i == n - 1 && dp[i][k]) {return true;}}}return false;}
}