字符串解码

Author: mayuanucas

src/main/java/algorithm/leetcode/Solution394.java

@@ -0,0 +1,50 @@
+package algorithm.leetcode;
+
+import java.util.LinkedList;
+
+/**
+ * @author: mayuan
+ * @desc: 字符串解码
+ * @date: 2019/03/15
+ */
+public class Solution394 {
+
+ public String decodeString(String s) {
+ if (null == s || 0 >= s.length()) {
+ return "";
+ }
+
+ String ans = "";
+ LinkedList<String> resStack = new LinkedList<>();
+ LinkedList<Integer> numberStack = new LinkedList<>();
+ int idx = 0;
+ while (idx < s.length()) {
+ char c = s.charAt(idx);
+ if (Character.isDigit(c)) {
+ int num = 0;
+ while (Character.isDigit(s.charAt(idx))) {
+ num = num * 10 + (s.charAt(idx) - '0');
+ ++idx;
+ }
+ numberStack.push(num);
+ } else if ('[' == c) {
+ resStack.push(ans);
+ ans = "";
+ ++idx;
+ } else if (']' == c) {
+ StringBuilder stringBuilder = new StringBuilder(resStack.pop());
+ int repeat = numberStack.pop();
+ while (0 < repeat--) {
+ stringBuilder.append(ans);
+ }
+ ans = stringBuilder.toString();
+ ++idx;
+ } else {
+ ans += c;
+ ++idx;
+ }
+ }
+
+ return ans;
+ }
+}