April 98 Question 3

• (a)

    final String TERMINATOR = "QUIT";
    final int MAX_RUNNER = 1000;
    Runner[] runners = new Runner[MAX_RUNNER];
    int rnum = 0;
  
    boolean notdone = true;
  
    while (notdone)
    {
     String name = stdin.readline();
  
     if (name.equals(TERMINATOR))
      notdone = false;
     else
     {
      int time = Integer.parseInt(stdin.readLine());
      runners[rnum] = new Runner(name, time);
      rnum++;
     }
    }
  

• (b)

    // first find fastest runner
    int fastest = 1000000;        // a big number
    for (int i = 0; i < rnum; i++)
    {
     if (runners[i].time <= fastest)
        fastest = runners[i].time;
    }
  
    // print out all runner's names with time <= fastest + 10%
    float close = fastest + (fastest*0.10);
    
     // go through the runners
    for (int i = 0; i < rnum; i++)
    {
     if (runners[i].time <= close)
        System.out.println(runners[i].name);
    }
  

• (c)

    void printFastest(Runner[] runners, int rnum)
    {
     final float fraction = 0.10;
     int fastnum = (int)rnum*fraction;
     Runner[] fastest = new Runner[fastnum];
     int current = 0;
  
     // read in first five runners as the fastest so far
     for (int i = 0; i < fastnum; i++)
     {
      fastest[i] = runners[i];
      current++;
     }
  
     // loop to read in the rest of the runners
     for (int i = current; i <= rnum; i++)
     {
      Runner nextrunner = runners[i];
      // 1) find the slowest runner in "fastest"
      // 2) if nextrunner is faster than than the slowest runner in fastest:
      //    - shift all runners in "fastest" after "slowest" up by one
      //      (effectively removing "slowest")
      //    - insert "nextrunner" at the end of "fastest"
      
      int slowest = 0;
      // loop to find the slowest runner in array "fastest"
      for (int j = 1; j < fastnum; j++)
      {
       if (fastest[j].time >= fastest[slowest].time)
  	slowest = j;	
      }	
       
      if (nextrunner.time <= fastest[slowest].time)
      {
       // shift the remaining runners in fastest up
       // (thereby removing slowest)
       for (int k = slowest+1; k < fastnum; k++)
       {
        fastest[k-1] = fastest[k];
       }
       // insert the current runner in the last position
       fastest[fastnum-1] = nextrunner;
      } // end if (nextrunner.time <= fastest[slowest].time)
     } // end for (int i = current; i <= rnum; i++)
     
     // print out all the runners in the array
     for (int i = 0; i < fastnum; i++)
     {
      System.out.println(fastest[i].name);
     }
    
    } // end printFastest