From ae7ea39966236965500faa96c42986bf35cc9af3 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Fri, 1 Apr 2016 21:31:28 +0200
Subject: Improve distribution of remaining spaces after base addition

Removed random utility class as it was over-designed.
---
 CMakeLists.txt          |  1 -
 src/line_accumulator.cc | 39 ++++++++++++++++++++++++++++++---------
 src/line_accumulator.h  | 11 +++++------
 src/random.cc           | 29 -----------------------------
 src/random.h            | 34 ----------------------------------
 5 files changed, 35 insertions(+), 79 deletions(-)
 delete mode 100644 src/random.cc
 delete mode 100644 src/random.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b24d21d..2a7b6a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,5 +14,4 @@ add_executable(
 	justify
 	justify.cc
 	src/line_accumulator.cc
-	src/random.cc
 )
diff --git a/src/line_accumulator.cc b/src/line_accumulator.cc
index b2facab..bc85e6c 100644
--- a/src/line_accumulator.cc
+++ b/src/line_accumulator.cc
@@ -3,9 +3,27 @@
 #include <iostream>
 #include <algorithm>
 
-LineAccumulator::LineAccumulator(const std::size_t max_length):
+namespace {
+
+std::vector<std::uint8_t> getRandomIndizes(
+	std::random_device& device,
+	const std::uint8_t n) {
+	std::vector<std::uint8_t> indizes(n);
+	std::iota(indizes.begin(), indizes.end(), 0);
+	std::shuffle(
+		indizes.begin(),
+		indizes.end(),
+		std::mt19937{device()}
+	);
+
+	return indizes;
+}
+
+}
+
+LineAccumulator::LineAccumulator(const std::uint8_t max_length):
 	max_length_{max_length},
-	random_{},
+	device_{},
 	length_{0},
 	tokens_{} { }
 
@@ -32,8 +50,8 @@ void LineAccumulator::discharge(const bool full) {
 		this->length_              -= this->tokens_.back().second;
 		this->tokens_.back().second = 0;
 
-		const std::size_t missing = this->max_length_ - this->length_;
-		const std::size_t base    = missing / (this->tokens_.size()-1);
+		const std::uint8_t missing = this->max_length_ - this->length_;
+		const std::uint8_t base    = missing / (this->tokens_.size()-1);
 
 		std::for_each(
 			this->tokens_.begin(),
@@ -44,12 +62,15 @@ void LineAccumulator::discharge(const bool full) {
 			}
 		);
 
-		auto range = this->random_.makeRange(0, this->tokens_.size()-2);
+		auto indizes = getRandomIndizes(this->device_, this->tokens_.size()-1);
 
-		while ( this->length_ < this->max_length_ ) {
-			this->tokens_[range.get()].second += 1;
-			this->length_                     += 1;
-		}
+		std::for_each(
+			indizes.begin(),
+			indizes.begin()+(this->max_length_ - this->length_),
+			[this](std::uint8_t x) {
+				this->tokens_[x].second += 1;
+			}
+		);
 	}
 
 	for ( const auto& token : this->tokens_ ) {
diff --git a/src/line_accumulator.h b/src/line_accumulator.h
index b3e78de..93ebfc0 100644
--- a/src/line_accumulator.h
+++ b/src/line_accumulator.h
@@ -3,21 +3,20 @@
 #include <tuple>
 #include <string>
 #include <vector>
-
-#include "random.h"
+#include <random>
 
 class LineAccumulator {
 	public:
-		LineAccumulator(const std::size_t max_length);
+		LineAccumulator(const std::uint8_t max_length);
 		~LineAccumulator();
 
 		void operator()(const std::string& word);
 
 	private:
-		const std::size_t max_length_;
+		const std::uint8_t max_length_;
 
-		utility::Random random_;
-		std::size_t     length_;
+		std::random_device device_;
+		std::uint8_t       length_;
 
 		std::vector<
 			std::pair<std::string, std::uint8_t>
diff --git a/src/random.cc b/src/random.cc
deleted file mode 100644
index dba3647..0000000
--- a/src/random.cc
+++ /dev/null
@@ -1,29 +0,0 @@
-#include "random.h"
-
-namespace utility {
-
-std::size_t Random::Range::get() {
-	return this->distribution_(*(this->generator_));
-}
-
-Random::Range::Range(
-	std::mt19937* const generator,
-	const std::size_t   a,
-	const std::size_t   b
-):
-	generator_(generator),
-	distribution_(a, b) { }
-
-Random::Random():
-	device_{},
-	generator_{device_()} { }
-
-Random::Range Random::makeRange(
-	const std::size_t a,
-	const std::size_t b) {
-	this->generator_.seed(this->device_());
-
-	return Range{&(this->generator_), a, b};
-}
-
-}
diff --git a/src/random.h b/src/random.h
deleted file mode 100644
index 73f3215..0000000
--- a/src/random.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#pragma once
-
-#include <random>
-
-namespace utility {
-
-class Random {
-	public:
-		class Range {
-			public:
-				std::size_t get();
-
-			protected:
-				friend class Random;
-
-				Range(std::mt19937* const, const std::size_t, const std::size_t);
-
-			private:
-				std::mt19937* const                        generator_;
-				std::uniform_int_distribution<std::size_t> distribution_;
-		};
-
-		Random();
-
-		Range makeRange(const std::size_t a, const std::size_t b);
-
-	private:
-		std::random_device device_;
-		std::mt19937       generator_;
-
-};
-
-
-}
-- 
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