# loop: stop if value repeats

조회 수: 7(최근 30일)
Niklas Kurz 2021년 1월 21일
답변: Jan 2021년 1월 24일
In my case this is based on
N = Number
G = Guess
x = 1:N
R= mod(G^x,N)
if R repeats I want the calculation mod(G^x,N) to stop and tell me the steps P that it needed to to get to R again
for example if R = 1, 4 3, 2, 1 -stop, P = 4
##### 댓글 수: 2표시숨기기 이전 댓글 수: 1
Jan 2021년 1월 24일
The question is not clear yet. This makes it hard to find an answer.

댓글을 달려면 로그인하십시오.

### 채택된 답변

Jan 2021년 1월 24일
N = Number;
G = Guess;
x = 1:N;
R = nan(1, N);
found = N;
for k = 1:N
R(k) = mod(G^x(k), N);
if any(R(1:k-1) == R(k))
found = k;
break
end
end
R = R(1:found)

댓글을 달려면 로그인하십시오.

### 추가 답변(1개)

Bob Thompson 2021년 1월 21일
I'm assuming you have all four of these commands within some kind of loop. Without the loop I have not tested what I'm going to suggest adding.
To do what you're asking you need to record all the values of R, this can be done by indexing R. If you aren't running an integer for loop, starting at 1, then you'll need to add a counter for each time you loop.
Then you just need an if check to determine if the loop needs to be broken.
N = Number
G = Guess
x = 1:N
R(count) = mod(G^x,N)
if sum(R==R(count))>1
P = length(R)-1;
break
end
end
##### 댓글 수: 3표시숨기기 이전 댓글 수: 2
Niklas Kurz 2021년 1월 23일
I want the loop to stop if it found a repeated number because I need it to count the period in order that I can continue processing wih it.

댓글을 달려면 로그인하십시오.

### 범주

Find more on Loops and Conditional Statements in Help Center and File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!