// CS100, Spring 2000, Solutions to Review questions for Prelim 3

// 1. Solution#1

//One way of doing it..
class RockPaperScissors {
    static void main(String[] args) {
        final int ROCK = 0, PAPER = 1, SCISSORS = 2, CHOICES = 3;
        final String choices = "rps"; // user's single-letter choices
	
	//Create array to determine winners
        boolean[][] win = // win[i][j] is whether i beats j
	{ // ROCK   PAPER   SCISSORS
	    { false, false, true }, // ROCK
	    { true, false, false }, // PAPER
	    { false, true, false } }; // SCISSORS
        final int TIE = 0, WIN = 1, LOSE = 2, OUTCOMES = 3;
        int[] outcomes = new int[OUTCOMES]; // # of ties, wins, losses
	so far
	    final String[] LABELS = { "tie(s)", "human win(s)", "computer win(s)" };
        boolean go = true; // whether to keep playing
	
	TokenReader in = new TokenReader(System.in);
	
	while (go) {
            int computer = (int) (Math.random()*CHOICES); // computer's choice
	    System.out.print("what is your choice of " + choices + "?");
            String s = in.readString().toLowerCase();
            char c = s.charAt(0);
            int human = choices.indexOf(c); // human's choice
            if (c == 'q') go = false;
            else if (human<0) System.out.println("invalid choice");
            else {
                System.out.print("computer chose " +
				 choices.charAt(computer));
                System.out.print(" you chose " + c);
                int outcome; // outcome of this game
                if (computer == c) outcome = TIE;
                else if (win[computer][human]) outcome = LOSE;
                else outcome = WIN;
                System.out.println("; outcome -- " + LABELS[outcome]);
                outcomes[outcome]++;
            }
        }
        for (int i = 0; i < OUTCOMES; i++)
            System.out.println(outcomes[i] + " " + LABELS[i]);
    }
}


// Solution#2

//Another way..


public class  RockPaperScissors {
    
    public static void main(String[] args) {
	
	TokenReader in = new TokenReader(System.in);
	
	String s;
	int ties=0,compwin=0, humanwin=0;
	
	//keep playing till bored
	
	do{
	    //Computer does a random selection betwee Rock(R),Paper(P) and
	    Scissors(S)
		double selector=Math.random()*3;
	    char Comp;
	    Comp= (selector>2)? 'R':((selector>1)? 'P':'S');
	    
	    //Prompt for input until correct input
	    System.out.println("Select one of Paper,Rock and Scissors");
	    s=in.readString();
	    s=s.toUpperCase();
	    char Human=s.charAt(0);
	    while(Human!='R'&& Human!='P' && Human!='S'){
		System.out.println("Select one of Paper,Rock and Scissors");
		s=in.readString();
		s=s.toUpperCase();
		Human=s.charAt(0);
	    }
	    
	    //blurt out choices
	    System.out.println("My choice: " +Comp);
	    System.out.println("Your Choice: "+Human);
	    
	    //decide winner
	    int winsel=Human-Comp;
	    //winsel={1,2,-3}=>comp wins, {-1,-2,3}=>human wins
	    
	    winsel=winsel*((2.5-winsel)>0? 1:-1);
	    //now winsel={1,2,3}=>comp wins, {-1,-2,-3}=>human wins
	    
	    if(winsel<0){
		System.out.println("OK, You win this time");
		humanwin++;}
	    else{
		if(winsel>0){
		    System.out.println("I win!!");
		    compwin++;}
		else{
		    System.out.println("Its a Tie!!");
		    ties++;}}
	    System.out.println("Play More?");
	    s=in.readString();}
	while(s.charAt(0)=='y'||s.charAt(0)=='Y');
	
	System.out.println("Report: We had "+(ties+humanwin+compwin) +" games.");
	System.out.println(" I won "+compwin+" times ");
	System.out.println(" You won "+humanwin+ " times ");
	System.out.println(" There were "+ties+" Tied games");
	
    }
}


// 2.
    
class Histogram {
    //print a formatted number upto 3 digits
    static void print(int n) {
        String s = "" + n;
        while (s.length() < 3) s = " " + s;
        System.out.print(s + " ");
    }
    static void main(String[] args) {
        TokenReader in = new TokenReader(System.in);
        int n = in.readInt(); // next input to process
        int next = n; // next number to print histogram for
        if (n>=0) print(n);
        while (n>0) {
            if (n == next) {
                System.out.print("*");
                n = in.readInt();
            } else {
                System.out.println();
                if (n>next) next++; else next--;
                print(next); // note: this will print an unneeded line
            }
	}
	System.out.println();
    }
}

// OR

class Histogram {
    static void print(int n) {
        String s = "" + n;
        while (s.length() < 3) s = " " + s;
        System.out.print(s + " ");
    }
    static void main(String[] args) {
        TokenReader in = new TokenReader(System.in);
        int n = in.readInt(); // next input to process
        int next = n; // next number to print histogram for
        String bar = ""; // bar of stars to print for next
        while (n>0) {
            if (n == next) {
                bar += "*";
                n = in.readInt();
            } else {
                print(next); System.out.println(bar);
                bar = "";
                if (n>next) next++; else next--;
            }
        }
        if (bar.length()>0) // print final bar
            { print(next); System.out.println(bar); }
    }
}

OR
    
// Using arrays: Review question 2
    
    public class rvw2arr {
	
	public static void main(String[] args) {
	    
	    TokenReader in = new TokenReader(System.in);
	    
	    final int LIMIT=1000;
	    int j,k,max_num=0;
	    int[] num = new int[LIMIT];  //atmost 3 digits long
	    
	    System.out.println("Input a sequence of non-negative #'s terminated by -1");
	    
	    //read numbers till -ve, calculate max
	    num[0]=in.readInt();
	    for(k=1;k<LIMIT && num[k-1]>=0;k++){
		max_num=Math.max(max_num,num[k-1]);
		num[k]=in.readInt();}
	    
	    //allocate max+1 counts
	    int[] num_count = new int[max_num+1];
	    
	    //cont occurences
	    for(k=0;k<LIMIT && num[k]>=0;k++)
		num_count[num[k]]++;
	    
	    //print out counts
	    for(k=0;k<=max_num;k++){
		System.out.print(" "+ k + " ");
		for (j=0;j<num_count[k];j++)
		    System.out.print("*");
		System.out.println();}
	    
	}
    }



// 3.

public class ISBN {
    
    public static void main(String[] args) {
	
	TokenReader in = new TokenReader(System.in);
	
	String s;int k;
	int[] isbnum = new int[10];
	
	System.out.println("Type q to quit or input next number");
	
	//Read in the String and quit if q
	s=in.readString();
	while(s.charAt(0)!='q'&&s.charAt(0)!='Q'){
	    if(s.length()==10){
		//Convert to array of integers--helps in processing
		for(k=0;k<10;k++)
		    isbnum[k]=(s.charAt(k)-'0');
		//System.out.println(isbnum[1]+""+isbnum[4]);
		//Check if isbn
		if(isbcheck(isbnum)==s.charAt(9))
		    System.out.println("That was a valid ISBN number");
		else
		    System.out.println("That was not valid");
	    }
	    else
		System.out.println("Need a 10 digit number");
	    System.out.println("Type q to quit or input next number");
	    s=in.readString();
	}
    }
    
    public static char isbcheck(int[] inpnum){
	//run the function specified
	int sum=0,k;
	for(k=0;k<9;k++)
	    sum += inpnum[k]*k;
	return (sum%11==10)? 'X':(char)(sum%11);
    }
}