Java | Leetcode Java题解之第514题自由之路

题目：

题解：

class Solution {public int findRotateSteps(String ring, String key) {int n = ring.length(), m = key.length();List<Integer>[] pos = new List[26];for (int i = 0; i < 26; ++i) {pos[i] = new ArrayList<Integer>();}for (int i = 0; i < n; ++i) {pos[ring.charAt(i) - 'a'].add(i);}int[][] dp = new int[m][n];for (int i = 0; i < m; ++i) {Arrays.fill(dp[i], 0x3f3f3f);}for (int i : pos[key.charAt(0) - 'a']) {dp[0][i] = Math.min(i, n - i) + 1;}for (int i = 1; i < m; ++i) {for (int j : pos[key.charAt(i) - 'a']) {for (int k : pos[key.charAt(i - 1) - 'a']) {dp[i][j] = Math.min(dp[i][j], dp[i - 1][k] + Math.min(Math.abs(j - k), n - Math.abs(j - k)) + 1);}}}return Arrays.stream(dp[m - 1]).min().getAsInt();}
}