recursion

问题 This question already has answers here : How does this recursion work? (11 answers) Closed last month . function findSolution(target) { function find(current, history) { if (current == target) {debugger; return history; } else if (current > target){ debugger; return null; } else{ debugger; return find(current + 5, "(" + history + " + 5)") || find(current * 3, "(" + history + " * 3)"); } } debugger; return find(1, "1"); } console.log(findSolution(13)); During it's working after it reaches find

问题 This question already has answers here : How does this recursion work? (11 answers) Closed last month . function findSolution(target) { function find(current, history) { if (current == target) {debugger; return history; } else if (current > target){ debugger; return null; } else{ debugger; return find(current + 5, "(" + history + " + 5)") || find(current * 3, "(" + history + " * 3)"); } } debugger; return find(1, "1"); } console.log(findSolution(13)); During it's working after it reaches find

问题 Given the head of a linked list and the int to search for as parameters, I need a method that will remove the first occurrence of this number in the list, and return the modified list. however i cannot modify the original list. I know how to remove the node from the list, but im not sure how i would keep the original list intact since this has to be done recursively. below is the method ** initially M is the original list. I dont know that it will still be the same list after calling the

问题 I am trying to find (using Python) all possible solutions to a maze. I have a DFS script that returns one solution. I am trying to adapt it but I'm really having a hard time wrapping my head around the whole recursion thing. Here's the code I have, which works for finding one possible solution using DFS: Any tips or help would be much appreciated! (The "lett" in the array can be ignored/considered regular "path") def DFS(x,y,Map): if (Map[x][y]=="exit"): #check if we're at the exit return [(x

问题 I have a specified JSON document, like this: { "user":"human1", "subsystems":[1,2,3], "query":{"AND":[ {"eq":["key1","val1"]}, {"eq":["key2","val2"]}, {"OR":[ {"eq":["subkey1","subval1"]}, {"eq":["subkey2","subval2"]}]} ] } } Expected transformation of the query field: (key1 eq val1 and key2 eq val2 and (subkey1 eq subval1 OR subkey2 eq subval2)) I am using Newtonsoft.Json ( JsonConvert.DeserializeObject ), and I don't understand how to transform this field. 回答1: Well, like most things, there

问题 I can't begin to understand how to approach this problem. Can someone help me to just point me in the direction as to how I can approach it? N tasks are given and there are M workers that are available. Each worker can takes different times to complete each task. The time taken by each worker for every task is given. At any time only one task can be worked on by only one worker. But the condition is once a worker has stopped working, he can't work on any task again. I want to find out what is

问题 I am teaching myself AP Computer Science A with the help of a textbook, YouTube, and worksheets found online. One of the worksheets was on recursion and asked me to convert the code below to recursion, however, neither the textbook or YouTube could explain how to convert from iteration to recursion. public static int iterative(int x){ int count=0; int factor=2; while(factor<x){ if(x%factor==0) count++; factor++; } return count; } The code below is my attempt, but I keep getting a

问题 I want to write a function which behaves exactly similar to the given function, except that it prints the time consumed in executing it. Just like this: >>> fib = profile(fib) >>> fib(20) time taken: 0.1 sec 10946 This is my code,and it will print message in each function call. import time def profile(f): def g(x): start_time = time.clock() value = f(x) end_time = time.clock() print('time taken: {time}'.format(time=end_time-start_time)) return value return g @profile def fib(n): if n is 0 or

问题 So I wrote a Fibonacci sequence function like this: CREATE OR REPLACE FUNCTION fibonacci (lastN INTEGER) RETURNS int AS $$ BEGIN WITH RECURSIVE t(a, b) AS ( VALUES(0,1) UNION ALL SELECT GREATEST(a, b), a + b AS a from t WHERE b < $1 ) SELECT a FROM t; END; $$ LANGUAGE plpgsql; But when I called: SELECT * FROM fibonacci(20); the console shows: ERROR: query has no destination for result data HINT: If you want to discard the results of a SELECT, use PERFORM instead. CONTEXT: PL/pgSQL function

问题 So I wrote a Fibonacci sequence function like this: CREATE OR REPLACE FUNCTION fibonacci (lastN INTEGER) RETURNS int AS $$ BEGIN WITH RECURSIVE t(a, b) AS ( VALUES(0,1) UNION ALL SELECT GREATEST(a, b), a + b AS a from t WHERE b < $1 ) SELECT a FROM t; END; $$ LANGUAGE plpgsql; But when I called: SELECT * FROM fibonacci(20); the console shows: ERROR: query has no destination for result data HINT: If you want to discard the results of a SELECT, use PERFORM instead. CONTEXT: PL/pgSQL function