[leetcode] Encode and Decode String

收录一个更加简单的方法（同样思想）

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public class Codec { // Encodes a list of strings to a single string. public String encode(List<String> strs) { StringBuilder sb = new StringBuilder(); for(String s : strs) { sb.append(s.length()).append('/').append(s); } return sb.toString(); } // Decodes a single string to a list of strings. public List<String> decode(String s) { List<String> ret = new ArrayList<String>(); int i = 0; while(i < s.length()) { int slash = s.indexOf('/', i); int size = Integer.valueOf(s.substring(i, slash)); ret.add(s.substring(slash + 1, slash + size + 1)); i = slash + size + 1; } return ret; } }

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public class Codec { // Encodes a list of strings to a single string. public String encode(List<String> strs) { if (strs == null || strs.size() == 0) return "#-1#"; String header = "#"; for (int i = 0; i < strs.size(); i++){ header = header+strs.get(i).length()+","; } header = header.substring(0, header.length()-1)+"#"; String body = ""; for (int i = 0; i < strs.size(); i++){ body += strs.get(i); } return header+body; } // Decodes a single string to a list of strings. public List<String> decode(String s) { int[]lengths = readHeader(s); List<String> result = new ArrayList<String>(); if (lengths[0] == -1) return result; int starting = lengths[lengths.length-1]; for (int i = 0; i < lengths.length-1; i++){ if (lengths[i] == 0){ result.add(""); }else{ result.add(s.substring(starting, starting+lengths[i])); } starting += lengths[i]; } return result; } int[] readHeader(String s){ int i = 2; for (; i < s.length() && s.charAt(i) != '#'; i++); String header = s.substring(1, i); String[]temp = header.split(","); int[]result = new int[temp.length+1]; for (int j = 0; j < temp.length; j++){ result[j] = (new Integer(temp[j])).intValue(); } result[result.length-1] = i+1;//starting index return result; } } // Your Codec object will be instantiated and called as such: // Codec codec = new Codec(); // codec.decode(codec.encode(strs));