CODEWITHSUNDEEP
javaloopsaverage
ZebraRuler
ZebraRuler

Reputation: 5

Not sure why this is not working

This is a program i'm stuck on for school. Can't figure out why it won't give me a average and a greatest. The program runs 50 times like i want it to but does not add a value to moves and total.

import java.util.*;

public class RandomWalk {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Random rand = new Random();

        int location;
        double average;
        int greatest=0;
        int moves = 0;
        int total = 0;
        int step;

        for (int i = 0; i < 50; i++) {

            location = 4;
            step = rand.nextInt((2 - 1) + 1) + 1;


            while (location < 1 || location > 7) {
                moves ++;
                if (step == 2){
                    location ++;    
                } else {
                    location --;
                }
                if (moves > greatest) {
                    greatest = moves;
                    total += moves;
                }
            }
        }

        average = total / 50;

        System.out.println("The greatest number of steps: " + greatest);
        System.out.println("The average number of steps:  " + average);

     }

}

fixed the for loop but it still does not give me the average and the greatest.

as for the while (location < 1 || location > 7) it should run till the person stands on location 1 or location 7.

here is the problem i was given:

In the "random walk", a person is placed at the center of a seven meter long bridge. Each step moves a person 1 meter either forward or backward at random. Create a randomwalk that determines how many steps the person will walk before taking a step off the bridge. Have the application average 50 trials, and display the average and the greatest number of steps.

thanks for helping...

if i change it to this: `import java.util.*;

public class RandomWalk2 {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Random rand = new Random();
    double average;
    int greatest=0;
    int moves;
    int total = 0;
    int step;

    step = rand.nextInt((2 - 1) + 1) + 1;

    int location; //location of man on bridge
    for(int i = 0; i < 50; i++)
    {
       moves = 0;
       moves++;
       location = 4;
       total += moves;
       while(true)
       {
          if (step == 2) {
           location++;
          } else {
           location--;
          }

         if((location < 1) || (location > 7)) break;
       }

      if(moves > greatest) {
      greatest = moves;

      }


      }

    average = total / 50;

    System.out.println("The greatest number of steps: " + greatest);
    System.out.println("The average number of steps:  " + average);


    }

}

` then it runs 50 times but the guy only moves 1 stop so my greatest and average always shows as 1.

Upvotes: 0

Views: 1146

Answers (3)

M7Jacks
M7Jacks

Reputation: 124

You need to understand the basics of a for loop.

for (initialization; termination; increment) { statement(s) }

When using this version of the for statement, keep in mind that:

The initialization expression initializes the loop; it's executed once, as the loop begins. When the termination expression evaluates to false, the loop terminates. The increment expression is invoked after each iteration through the loop; it is perfectly acceptable for this expression to increment or decrement a value.

The following link should be helpful:

Java for loops

Upvotes: 1

RyanS
RyanS

Reputation: 4194

location = 4;
step = rand.nextInt((2 - 1) + 1) + 1;
while (location < 1 || location > 7) {
    ..
}

When will location be less than 1 or greater than 7?

Also the for loop as mentioned by rgettman

Upvotes: 0

rgettman
rgettman

Reputation: 178343

No, it doesn't loop 50 times, because your for loop condition is incorrect. The for loop continues iterating if the condition is true, not false. Change your condition from

for (int i = 0; i == 50; i++) {

to

for (int i = 0; i < 50; i++) {

Then it will run until i < 50 is false (50 times).

Upvotes: 4

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