資訊專欄INFORMATION COLUMN
Problem
Given an integer array, find the top k largest numbers in it.
ExampleGiven [3,10,1000,-99,4,100] and k = 3.
Return [1000, 100, 10].
Heap Priority Queue
Solutionpublic class Solution {
public int[] topk(int[] nums, int k) {
//construct comparator, then priority-queue
Comparator comparator = new Comparator() {
public int compare(Integer v1, Integer v2) {
//can also use `return v2-v1;`
if (v1 < v2) {
return 1;
} else if (v1 > v2) {
return -1;
} else {
return 0;
}
}
};
PriorityQueue maxHeap = new PriorityQueue<>(k, comparator);
//use maxHeap to get top k largest
for (int num: nums) {
maxHeap.offer(num);
}
//save to res array
int[] res = new int[k];
for (int i = 0; i < k; i++) {
res[i] = maxHeap.poll();
}
return res;
}
}
文章版權(quán)歸作者所有，未經(jīng)允許請勿轉(zhuǎn)載,若此文章存在違規(guī)行為，您可以聯(lián)系管理員刪除。
轉(zhuǎn)載請注明本文地址：http://systransis.cn/yun/68082.html
Problem Implement a data structure, provide two interfaces: add(number). Add a new number in the data structure.topk(). Return the top k largest numbers in this data structure. k is given when we crea...
Problem Find the largest palindrome made from the product of two n-digit numbers. Since the result could be very large, you should return the largest palindrome mod 1337. Example Input: 2Output: 987Ex...
摘要：只有當(dāng)位數(shù)時，才打印數(shù)字。首先分析邊界，應(yīng)該，然后用存最高位。用函數(shù)對進(jìn)行遞歸運算，同時更新結(jié)果數(shù)組。更新的過程歸納一下，首先，計算最高位存入，然后，用到倍的和之前里已經(jīng)存入的所有的數(shù)個循環(huán)相加，再存入，更新，計算更高位直到等于 Problem Print numbers from 1 to the largest number with N digits by recursion. ...
摘要：可以不要用太簡單的方法。先把它裝滿，再和隊列頂端的數(shù)字比較，大的就替換掉，小的就。遍歷完所有元素之后，頂部的數(shù)就是第大的數(shù)。 Problem Find K-th largest element in an array. Example In array [9,3,2,4,8], the 3rd largest element is 4.In array [1,2,3,4,5], the...
Problem Given two numbers n and k. We need to find out if n can be written as sum of k prime numbers. Example Given n = 10, k = 2Return true // 10 = 5 + 5 Given n = 2, k = 2Return false Solution pub...
閱讀 2532·2021-11-24 09:39
閱讀 3566·2019-08-30 15:53
閱讀 655·2019-08-29 15:15
閱讀 2959·2019-08-26 13:23
閱讀 3299·2019-08-26 10:48
閱讀 696·2019-08-26 10:31
閱讀 831·2019-08-26 10:30
閱讀 2411·2019-08-23 18:32
