UVa Problem 110 – Meta-Loopless Sorts

// UVa Problem 110 - Meta-Loopless Sorts// Verdict: Accepted// Submission Date: 2011-11-25// UVa Run Time: 0.196s//// 著作權（C）2011，邱秋。metaphysis # yeah dot net//// [解題方法]// 啊哈，又是一道很有意思的類比題。本題解是依照題目所給的樣本類比產生插入排序的 Pascal 程式。#include <iostream>using namespace std;int n;string tab(2, ' ');string substr(string s, int start, int length){if (start >= s.length())return "";return s.substr(start, length);}void writeln(string space, string sequences){cout << space << "writeln(";for (int i = 0; i < sequences.length(); i++)cout << (i ? "," : "") << sequences[i];cout << ")\n";}void sort(string space, string sequences){char c = (char) ('a' + sequences.length());for (int i = sequences.length(); i >= 0; i--){if (i){cout << space << "if " << sequences[(i ? (i - 1) : i)];cout << " < " << c << " then\n";}string tmp = substr(sequences, 0, i) + c +substr(sequences, i, sequences.length() - i);if (tmp.length() == n)writeln(space + (i ? tab : ""), tmp);elsesort(space + tab, tmp);if (i){cout << space << "else\n";space += tab;}}}int main(int argc, char const *argv[]){int cases;bool printBlankLine = false;cin >> cases;while (cases--){cin >> n;if (printBlankLine)cout << "\n";elseprintBlankLine = true;cout << "program sort(input,output);\n";cout << "var\n";for (int i = 0; i < n; i++)cout << (i ? "," : "") << (char) ('a' + i);cout << " : integer;\n";cout << "begin\n";cout << (tab + "readln(");for (int i = 0; i < n; i++)cout << (i ? "," : "") << (char) ('a' + i);cout << ");\n";sort("", "");cout << "end.\n";}return 0;}