Create Blocksort.cpp

Cpp/Blocksort.cpp

@@ -0,0 +1,48 @@
+#include <vector>
+#include <iostream>
+#include <algorithm>
+
+class Blocksort
+{
+public:
+	static std::string encode(const std::string &input,int &top);
+	static std::string decode(const std::string &input,int top);
+};
+
+
+std::string Blocksort::encode(const std::string &input, int &top)
+{
+	std::string buff,result;
+	buff = input + input;
+	std::vector<std::string> vectemp;
+
+	for(int i=0; i < buff.size()/2;++i){
+		std::string temp=buff.substr(i,input.size());	
+		vectemp.push_back(temp);
+	}
+
+	std::stable_sort(vectemp.begin(),vectemp.end());
+
+	for(int i=0; i < vectemp.size();++i){
+		if( input == vectemp[i] ) top = i;
+		result += *(vectemp[i].end()-1);
+	}
+	return result;
+}
+
+std::string Blocksort::decode(const std::string &input,int top)
+{
+	std::string result,inputs=input;
+	std::vector<int> idx(input.size());
+  for (int i = 0; i != idx.size(); ++i) idx[i] = i;
+	std::stable_sort(idx.begin(),idx.end(),
+			[inputs](int i1,int i2)	{return inputs[i1] < inputs[i2];});
+
+	int p = top;
+	for(int i=0;i<input.size();++i) {
+		p = idx[p];
+		result += inputs[p];
+	}
+
+	return result;
+}