starZ.cpp

// starZ.cpp, 4/21/18, Mason Corey, A demonstration of ASCII Art printing C characters

#include <iostream>
#include <cstdlib>
#include <string>
using namespace std;

void assertEquals(string expected, string actual, string message);
string starZ(int width);
void runTests(void);

// Write starZ per specifictions at 
// https://foo.cs.ucsb.edu/16wiki/index.php/F14:Labs:lab04
// and so that internal tests pass, and submit.cs system tests pass


string starZ(int width)
{
  string result="";
  if(width>=3)  {
    for (int i = 0; i < width; i++) {
      result+="*";
    }
    result+="\n";

    for(int i=2; i<width; i++)  {
      int num_Spaces = width-i;
      for(int k=0; k<num_Spaces; k++)  {
        result+=" ";
      }
      result+="*";
      for(int k=0; k<(i-1); k++)  {
        result+=" ";
      }
      result+="\n";
    }

    for (int i = 0; i < width; i++) {
      result+="*";
    }
    result+="\n";
  }
  return result;
}

// Test-Driven Development; check expected results against actual

void runTests(void) {

  // The following line works because in C and C++ when string literals
  // are separated only by whitespace (space, tab, newline), they 
  // automatically get concatenated into a single string literal

  string starZ3Expected = 
    "***\n"
    " * \n"
    "***\n";
  
  assertEquals(starZ3Expected,starZ(3),"starZ(3)");

  string starZ4Expected = 
    "****\n"
    "  * \n"
    " *  \n"
    "****\n";
  
  assertEquals(starZ4Expected,starZ(4),"starZ(4)");

  assertEquals("",starZ(0),"starZ(0)");
  assertEquals("",starZ(2),"starZ(2)");
}

// Test harness

void assertEquals(string expected, string actual, string message="") {
  if (expected==actual) {
    cout << "PASSED: " << message << endl;;
  } else {
    cout << "   FAILED: " << message << endl << "   Expected:[\n" << expected << "] actual = [\n" << actual << "]\n" << endl;
  }
}


// Main function
int main(int argc, char *argv[])
{
  
  if (argc!=2) {
    cerr << "Usage: " << argv[0] << " width" << endl;
    exit(1);
  }
  
  int width = atoi(argv[1]);
  // If the program is executed with parameters -1 -1 unit test
  // the starL() function using our automated test framework
  if (width==-1) {
    runTests();
    exit(0);
  }

  cout << starZ(width);
  return 0;
}