adding cs142 code

cs142/smcquay/midterm2/Makefile

@@ -0,0 +1,29 @@
+CXX=g++
+CPPFLAGS=-Wall -g -std=c++0x
+SOURCES=main.cc util.cc
+OBJECTS=$(SOURCES:.cc=.o)
+EXE=app
+
+all: $(EXE) test
+
+main.o: main.cc util.o
+util.o: util.h util.cc
+unittest: util.o unittest.cc
+
+$(EXE): $(OBJECTS)
+	$(CXX) $(LDFLAGS) $(OBJECTS) -o $@
+
+clean:
+	@rm -vf *.o
+	@rm -rvf *.dSYM
+	@rm -vf $(EXE)
+	@rm -vf unittest
+
+test: unittest
+	./unittest
+
+debug: $(EXE)
+	gdb $(EXE)
+
+valgrind: $(EXE)
+	valgrind --tool=memcheck --leak-check=yes ./$(EXE)

cs142/smcquay/midterm2/main.cc

@@ -0,0 +1,22 @@
+#include <string>
+#include <iostream>
+#include <cstdlib>
+
+using namespace std;
+
+#include "util.h"
+
+const string usage = "usage: app <number of people> <step>";
+
+int main(int argc, char * argv []) {
+    if(argc != 3) {
+        cerr << usage << endl;
+        return 1;
+    }
+    int number_of_people = atoi(argv[1]);
+    int step = atoi(argv[2]);
+    vector<bool> people(number_of_people, true);
+    vector<int> loosers = _play_game(people, step);
+    cout << loosers[loosers.size()-1] << endl;
+    return 0;
+}

cs142/smcquay/midterm2/unittest.cc

@@ -0,0 +1,27 @@
+#include <string>
+#include <cassert>
+
+using namespace std;
+
+#include "util.h"
+
+
+int main(int argc, char * argv []) {
+    bool verbose = false;
+    if(argc > 1)
+        verbose = true;
+    assert(9  == _test_run(10, 1,  verbose));
+    assert(3  == _test_run(10, 3,  verbose));
+    assert(9  == _test_run(10, 12, verbose));
+    assert(19 == _test_run(20, 3,  verbose));
+    assert(4  == _test_run(15, 7,  verbose));
+    for(int i=0; i >= -1; i--) {
+        try {
+            _test_run(1500000, i);
+        }
+        catch(string e) {
+            assert(e == "rule violation: m > 0");
+        }
+    }
+    return 0;
+}

cs142/smcquay/midterm2/util.cc

@@ -0,0 +1,56 @@
+#include <iostream>
+#include <string>
+#include <vector>
+using namespace std;
+
+#include "util.h"
+
+ostream & operator<<(ostream & os, vector<int> & v) {
+    os << "[";
+    for(unsigned int i = 0; i < v.size(); i++) {
+        os << v[i];
+        if(i != v.size() - 1) {
+            os << ", ";
+        }
+    }
+    os << "]";
+    return os;
+}
+
+int _increment_to_next_looser(const vector<bool> & players,
+                                            int start, const int step) {
+    int counter = 0;
+    // the test examples in the pdf have us start by killing the m-1th person
+    // offset by one for some dumb reason
+    int attempt = start - 1;
+    while(counter != step) {
+        attempt = (attempt + 1) % players.size();
+        if(players[attempt]) {
+            counter++;
+        }
+    }
+    return attempt;
+}
+
+vector<int> _play_game(vector<bool> & players, int step) {
+    vector<int> loosers;
+    int token = 0;
+    while(loosers.size() < players.size()) {
+        token = _increment_to_next_looser(players, token, step);
+        players[token] = false;
+        loosers.push_back(token);
+    }
+    return loosers;
+}
+
+int _test_run(int n, int m, bool verbose) {
+    if(m < 1) {
+        throw string("rule violation: m > 0");
+    }
+    vector<bool> players(n, true);
+    vector<int> loosers = _play_game(players, m);
+    if(verbose) {
+        cout << loosers << endl;
+    }
+    return loosers[loosers.size()-1];
+}

cs142/smcquay/midterm2/util.h

@@ -0,0 +1,16 @@
+#ifndef __UTIL_H__
+#define __UTIL_H__
+
+#include <vector>
+#include <iostream>
+
+using namespace std;
+
+ostream & operator<<(ostream &, vector<bool> &);
+
+vector<int> _play_game(vector<bool> & players, const int step);
+int _increment_to_next_looser(const vector<bool> & players, int start, const int step);
+
+int _test_run(int n, int m, bool verbose=false);
+
+#endif