1. PermCheck Check whether array A is a permutation. Task Score 70% Correctness 80% Performance 60% A non-empty array A consisting of N integers is given. A permutation is a sequence containing each element from 1 to N once, and only once. For example, array A such that: A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2 is a permutation, but array A such that: A[0] = 4 A[1] = 1 A[2] = 3 is not a permutation, because value 2 is missing. The goal is to check whether array A is a permutation. Write a function: class Solution { public int solution(int[] A); } that, given an array A, returns 1 if array A is a permutation and 0 if it is not. For example, given array A such that: A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2 the function should return 1. Given array A such that: A[0] = 4 A[1] = 1 A[2] = 3 the function should return 0. Write an efficient algorithm for the following assumptions: N is an integer within the range [1..100,000]; each element of array A is an integer within the range [1..1,000,000,000].
时间: 2024-01-21 20:02:32 浏览: 48
题目大意:
给定一个由N个整数组成的非空数组A,判断A是否为一个排列。排列是一个序列,其中包含1到N的每个元素,每个元素恰好出现一次。
如果是排列,返回1,否则返回0。
解题思路:
题目要求判断一个数组是否为排列,也就是判断数组中是否包含1到N的每个元素,每个元素恰好出现一次。我们可以先对数组进行排序,然后遍历数组,判断当前元素是否等于其下标加1。如果不等于,则说明当前元素缺失或者重复出现,不是排列。
如果遍历完数组都没有发现问题,则说明数组是排列。
时间复杂度为O(NlogN),因为需要对数组进行排序。
Java代码实现:
```
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for(int i = 0; i < A.length; i++) {
if(A[i] != i + 1) {
return 0;
}
}
return 1;
}
}
```
相关问题
GAhalf - Genetic operators for real, binary, and permutation based %encodings.
"GAhalf" 是一个用于实数、二进制和排列编码的遗传算法的遗传操作符。
遗传算法是一种基于模拟生物进化过程的优化算法。它通过模拟遗传操作(如交叉、变异和选择)来生成新的个体,并逐代优化解空间中的候选解。
"GAhalf" 提供了适用于不同编码类型的遗传操作符。具体包括:
1. 实数编码(Real Encoding):适用于处理实数型变量的遗传操作符。这些操作符可以对实数编码的个体进行交叉、变异和选择等操作。
2. 二进制编码(Binary Encoding):适用于处理二进制型变量的遗传操作符。这些操作符可以对二进制编码的个体进行交叉、变异和选择等操作。
3. 排列编码(Permutation Encoding):适用于处理排列型变量的遗传操作符。这些操作符可以对排列编码的个体进行交叉、变异和选择等操作。
通过使用不同类型的遗传操作符,"GAhalf" 可以适应不同类型的问题和编码方式,从而进行有效的优化搜索。
input a string(no more than 10characters),select m char from the string,output the permutation characters in lexicographic order.
Sure, I can help you with that! Here is a Python code snippet that should do the trick:
``` python
from itertools import permutations
string = input("Please enter a string (no more than 10 characters): ")
m = int(input("Please enter the number of characters to select: "))
perms = sorted([''.join(p) for p in permutations(string, m)])
print("Permutations in lexicographic order:")
for perm in perms:
print(perm)
```
This code prompts the user to input a string and the number of characters to select from that string. It then generates all possible permutations of the selected characters and sorts them in lexicographic order using the `sorted` function. Finally, it prints out each permutation in the desired order.
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