개발잡부

맵리듀스 세이프모드 # 세이프 모드 상태 확인 $ hdfs dfsadmin -safemode get Safe mode is OFF # 세이프 모드 진입 $ hdfs dfsadmin -safemode enter Safe mode is ON # 세이프 모드 해제 $ hdfs dfsadmin -safemode leave Safe mode is OFF 데이터블록 The filesystem under path '/user/hadoop' is CORRUPT # 커럽트 상태의 파일 삭제 $ hdfs fsck -delete # /user/hadoop/ 의 복제 개수를 5로 조정 $ hadoop fs -setrep 5 /user/hadoop/ # /user/hadoop/ 하위의 모든 파일의 복제 개수를 조정 $ hado..

A string S consisting of N characters is called properly nested if: S is empty; S has the form "(U)" where U is a properly nested string; S has the form "VW" where V and W are properly nested strings. For example, string "(()(())())" is properly nested but string "())" isn't. Write a function: class Solution { public int solution(String S); } that, given a string S consisting of N characters, re..

You are given two non-empty arrays A and B consisting of N integers. Arrays A and B represent N voracious fish in a river, ordered downstream along the flow of the river. The fish are numbered from 0 to N − 1. If P and Q are two fish and P < Q, then fish P is initially upstream of fish Q. Initially, each fish has a unique position. Fish number P is represented by A[P] and B[P]. Array A contains ..

A string S consisting of N characters is considered to be properly nested if any of the following conditions is true: S is empty; S has the form "(U)" or "[U]" or "{U}" where U is a properly nested string; S has the form "VW" where V and W are properly nested strings. For example, the string "{[()()]}" is properly nested but "([)()]" is not. Write a function: class Solution { public int solution..

public static int solution(int[] A) { // write your code in Java SE 8 int N = A.length; long[] lower = new long[N]; long[] upper = new long[N]; for (int i = 0; i = lower[j]) { intersection += j; inte..

An array A consisting of N integers is given. A triplet (P, Q, R) is triangular if 0 ≤ P A[R], A[Q] + A[R] > A[P], A[R] + A[P] > A[Q]. For example, consider array A such that: A[0] = 10 A[1] = 2 A[2] = 5 A[3] = 1 A[4] = 8 A[5] = 20 Triplet (0, 2, 4) is triangular. Write a function: class Solution { public int solution(int[] A); } that, given an array A consisting o..

A non-empty array A consisting of N integers is given. The product of triplet (P, Q, R) equates to A[P] * A[Q] * A[R] (0 ≤ P < Q < R < N). For example, array A such that: A[0] = -3 A[1] = 1 A[2] = 2 A[3] = -2 A[4] = 5 A[5] = 6 contains the following example triplets: (0, 1, 2), product is −3 * 1 * 2 = −6 (1, 2, 4), product is 1 * 2 * 5 = 10 (2, 4, 5), product is 2 * 5 * 6 = 60 Your goal is to fi..

Write a function class Solution { public int solution(int[] A); } that, given an array A consisting of N integers, returns the number of distinct values in array A. For example, given array A consisting of six elements such that: A[0] = 2 A[1] = 1 A[2] = 1 A[3] = 2 A[4] = 3 A[5] = 1 the function should return 3, because there are 3 distinct values appearing in array A, namely 1, 2 and 3. Write a..

A non-empty array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P < Q < N, is called a slice of array A (notice that the slice contains at least two elements). The average of a slice (P, Q) is the sum of A[P] + A[P + 1] + ... + A[Q] divided by the length of the slice. To be precise, the average equals (A[P] + A[P + 1] + ... + A[Q]) / (Q − P + 1). For example, arra..

Write a function: class Solution { public int solution(int A, int B, int K); } that, given three integers A, B and K, returns the number of integers within the range [A..B] that are divisible by K, i.e.: { i : A ≤ i ≤ B, i mod K = 0 } For example, for A = 6, B = 11 and K = 2, your function should return 3, because there are three numbers divisible by 2 within the range [6..11], namely 6, 8 and 1..