How to write a method that returns true if no row is longer than a preceding row, otherwise false?

Question

Say, if I have a 2D array:

int[][] s = {{1, 4, 5, 10, 11}, {2, 6, 8}, {3, 9, 12}, {7}};

and I want to write a method that makes sure the next row has a shorter length than the rest of the array how would I go about doing so?

Basically how would I write a method that returns true if no row is longer than a preceding row, and false otherwise?

Here is my logic even though I'm far off, just don't understand logically how to go about it I guess.

 public static boolean rowDecrease(int[][] t){
     //result empty array here
     for (int j = 0; j < t.length; j++) {
      for (int i = 0; i< t[i].length; i++) { // Sum of Columns
        if (t[i].length>result){
          result = t[i].length;
          return false;
        }
        if (t[i].length<result){
          result = t[i].length;
          return true;
        }


        }

      }

ok, and what exactly is stopping you? what do you have so far? — Stultuske, Apr 07 '16 at 06:41
you can get the length of the inner arrays with `s[i].length`. — SomeJavaGuy, Apr 07 '16 at 06:42
public static boolean rowLengthsDecrease(int[][] t){ //array result for (int j = 0; j < t.length; j++) { for (int i = 0; i< t[i].length; i++) { // Sum of Columns if (t[i].length>result){ result = t[i].length; return false; } if (t[i].length — Ella Donaldson, Apr 07 '16 at 06:47
There is an edit link under the text of the question. Please put your code into your question, not the comments — OneCricketeer, Apr 07 '16 at 06:49
Welcome to Stack Overflow! Please take the [tour], have a look around, and read through the [help], in particular [*How do I ask a good question?*](/help/how-to-ask) — T.J. Crowder, Apr 07 '16 at 06:49
*"...the next row has a shorter length than the rest of the array..."* "next" after what? — T.J. Crowder, Apr 07 '16 at 06:50

score 0 · Answer 1 · answered Apr 07 '16 at 06:49

0

I think that a code similar to this would resolve your question:

boolean resultado = true;

for(int i = 1; i < s.length; i++){
    if(s[i].length >= s[i-1].length) return false;
}

return true;

answered Apr 07 '16 at 06:49

Wakachopo

149
7

score 0 · Answer 2 · answered Apr 07 '16 at 06:49

0

Please make an attempt or present a problem with existing code before posting in the future. We'll have to start sending you invoices otherwise.

public boolean shorterThanTheRest(int[][] s){
    int shortestLength = s[0].length + 1;
    for(int i = 0; i < s.length; i++)
        if(s[i].length < shortestLength)
            shortestLength = s[i].length;
        else
            return false;
     return true;
}

answered Apr 07 '16 at 06:49

Zulfe

820
7
25

Buddy, couldn't this have been somewhat simpler? Like, maybe at each index `i`, check if the length of the previous index `i-1` is greater than or equal. If not, return `false`. Return `true` outside the loop. – Debosmit Ray Apr 07 '16 at 06:55
@DebosmitRay I realized that after I had posted it; however, since another user posted the more simple method you described, I left my answer up just to show that it can be approached differently. But yes, since the criteria is to determine if the length of rows is continuously decreasing, your method is best. – Zulfe Apr 07 '16 at 06:58
Haha, I just saw that post. I see what you are saying, @Zulfe. :) – Debosmit Ray Apr 07 '16 at 07:00

score 0 · Answer 3 · edited Apr 07 '16 at 06:57

0

You could do this using Java Stream:

int[][] s = {{1, 4, 5, 10, 11}, {2, 6, 8}, {3, 9, 12}, {7}};
List<Integer> S = Arrays.stream(s).map(i->i.length).collect(Collectors.toList());
boolean is = IntStream.range(0, S.size()).skip(1).allMatch(i->S.get(i)<=S.get(i-1));

I hope it helps.

edited Apr 07 '16 at 06:57

Gyanendra Dwivedi

5,511
2
27
53

answered Apr 07 '16 at 06:51

joel314

1,060
1
8
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How to write a method that returns true if no row is longer than a preceding row, otherwise false?

3 Answers3